Initial Study/Mitigated Negative Declaration
March 14, 2008
Mammoth Yosemite Airport Regional Air Service
Prepared for: Town of Mammoth Lakes
Prepared by: RBF Consulting
DRAFT INITIAL STUDY/MITIGATED NEGATIVE DECLARATION
Mammoth Yosemite Airport Regional Air Service
LEAD AGENCY:
Town of Mammoth Lakes 437 Old Mammoth Road, Suite R Mammoth Lakes, California 93546 Contact: Ms. Karen Johnston 760.934.8989, Ext. 228
PREPARED BY:
RBF Consulting 14725 Alton Parkway Irvine, California 92718 Contacts: Mr. Glenn Lajoie, AICP Mr. Eddie Torres, INCE 949.472.3505
March 14, 2008
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TABLE OF CONTENTS
1.0 Introduction ...... 1
1.1 Statutory Authority and Requirements...... 2 1.2 Purpose ...... 2 1.3 Reference Documents ...... 5
2.0 Project Description...... 10
2.1 Project Location and Setting ...... 10 2.2 Project Characteristics...... 15 2.3 Background and History...... 18 2.4 Agreements, Permits, and Approvals...... 20
3.0 Initial Study Checklist ...... 21
3.1 Background...... 21 3.2 Environmental Factors Potentially Affected...... 22 3.3 Lead Agency Determination...... 22 3.4 Evaluation of Environmental Impacts...... 23
4.0 Environmental Analysis...... 32
4.1 Aesthetics ...... 32 4.2 Agriculture Resources...... 36 4.3 Air Quality ...... 37 4.4 Biological Resources ...... 51 4.5 Cultural Resources ...... 58 4.6 Geology and Soils...... 59 4.7 Hazards and Hazardous Materials...... 63 4.8 Hydrology and Water Quality ...... 69 4.9 Land Use and Planning...... 75 4.10 Mineral Resources...... 78 4.11 Noise ...... 79 4.12 Population and Housing...... 86 4.13 Public Services ...... 88 4.14 Recreation ...... 90 4.15 Transportation/Traffic...... 91 4.16 Utilities and Service Systems...... 103 4.17 Mandatory Findings of Significance...... 105
5.0 Inventory of Mitigation Measures ...... 106
6.0 References...... 107
7.0 Report Preparation Personnel...... 109
8.0 Consultant Recommendation...... 110
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9.0 Appendices
9.1 Air Quality Data 9.2 Noise Data 9.3 Traffic Impact Analysis
JN 10-106064 - ii - March 14, 2008 LIST OF EXHIBITS
1 Regional Vicinity...... 11
2 Local Vicinity ...... 12
3 Existing Airport Facilities...... 13
4 Existing Land Use...... 14
5 Proposed Passenger Terminal Improvements...... 16
LIST OF TABLES
2-1 Summary of Development Proposals...... 17
AQ-1 Air Pollutant Emissions for the 2005 Existing Condition...... 42
AQ-2 Air Pollutant Emissions for the 2002 Project ...... 42
AQ-3 Air Pollutant Emissions for the 2009 and 2015 Conditions...... 43
AQ-4 Applicable Global Climate Change Strategies ...... 46
AQ-5 Potential Greenhouse Gas Reduction Measures...... 49
N-1 Existing Impacts to Land Use ...... 81
N-2 Proposed Project Impacts to Land Use...... 82
N-3 Existing Traffic Noise Levels...... 83
N-4 Future Traffic Noise Scenarios ...... 83
T-1 Existing Intersection LOS Summary ...... 94
T-2 Project Trip Generation ...... 94
T-3 Existing Plus Project Intersection LOS Summary ...... 95
T-4 Cumulative Trip Generation...... 97
T-5 Year 2006 Cumulative Intersection LOS Summary...... 98
T-6 Year 2025 Intersection LOS Summary ...... 99
T-7 Year 2025 Plus Project Intersection LOS Summary...... 100
JN 10-106064 - iii - March 14, 2008 LIST OF ACRONYMNS
AB Assembly Bill ACI Airports Council International ACZP Airport Height Restrictions Zone ADD Airport Development District ADT Average Daily Trips AEP Airport Emergency Plan AGL Above ground level ALUC Mono County Airport Land Use Commission ALUP Airport Land Use Plan APE Area of Potential Effects APU Auxiliary power units AQMP Air Quality Management Plan ARFF Aircraft Rescue and Fire Fighting
Basin Great Basin Valley Air Basin BLM Bureau of Land Management BMP Best Management Practice
CAA Federal Clean Air Act Caltrans California Department of Transportation CARB California Air Resources Board CCAT California Climate Action Team CCR California Code of Regulations CEQA California Environmental Quality Act CHP California Highway Patrol CNEL Community Noise Equivalent Level CPUC California Public Utilities Commission
DHC de Havilland Canada
EA Environmental Assessment EDMS Emissions Dispersion & Modeling System EIR Environmental Impact Report EIS Environmental Impact Statement EO Executive Order EOP Emergency Operations Plan EPA U.S. Environmental Protection Agency
FAA U.S. Department of Transportation Federal Aviation Administration FBO Fixed base operator FEMA Federal Emergency Management Agency FONSI Finding of No Significant Impact
GA General Aviation GBUAPCD Great Basin Unified Air Pollution Control District GCC Global Climate Change GHG Greenhouse gases GPD Gallons per day GPEIR General Plan Environmental Impact Report GPS Global Positioning System
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LIST OF ACRONYMNS
GSE Ground Support Equipment GWP Global Warming Potential
ICAO International Civil Aviation Organization IPCC Intergovernmental Panel on Climate Change ITE Institute of Transportation Engineers
HCM Highway Capacity Manual HCS2000 Highway Capacity Software
LADWP Los Angeles Department of Water and Power LAX Los Angeles International Airport LOS Level of service LTO Landing and Take Off
MCSD Mono County Sheriff’s Department MLFPD Mammoth Lakes Fire Protection District MLPD Mammoth Lakes Police Department MMH Mammoth Yosemite Airport MMSA Mammoth Mountain Ski Area MOU Memorandum of Understanding MPH Miles per hour
NEPA National Environmental Policy Act NPDES National Pollutant Discharge Elimination System
OPR California Office of Planning and Research
PAOT People at One Time
ROD Record of Decision RWQCB Regional Water Quality Control Board
SB Senate Bill SCH State Clearinghouse SF Square feet SHPO State Historic Preservation Office SNARL Sierra Nevada Aquatic Research Laboratory SPCC Spill Prevention Control and Countermeasure SWPPP Storm Water Pollution Prevention Plan
TIA Traffic Impact Analysis TSA Transportation Security Administration TSE Traffic Safety Engineers
UBC Uniform Building Code USDA-FS U.S. Department of Agriculture - Forest Service USFWS United States Fish and Wildlife Service
VMT Vehicle miles traveled
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1.0 INTRODUCTION
The Project involves the Town of Mammoth Lakes’ (Town) proposal to reinitiate regularly scheduled commercial air service into the Mammoth Yosemite Airport (Airport), which the Town has owned and operated since 1992, and which had regularly scheduled commercial air service in the 1980s and 1990s. Horizon Air would begin service in December 2008 with two daily flights from Los Angeles International Airport (LAX) to Mammoth during the winter ski season. It is estimated that this would result in a maximum of 10,214 annual enplanements. Winter ski service is projected to increase to a maximum of eight flights per day by the year 2011, which is estimated to result in 60,928 annual enplanements. The aviation activity forecast also considers the addition of two flights per day during the summer months, beginning in 2012, bringing the annual enplanements to a total of up to 67,168, and 17,482 annual aircraft operations.
The Town previously analyzed the proposal to reinitiate regularly scheduled commercial air service under the California Environmental Quality Act (CEQA) in 2002. Specifically, the Town certified a Final Supplement to Subsequent Environmental Impact Report (2002 Supplement) on November 6, 2002.1 This document analyzed a much greater amount of air service, with up to 333,000 annual enplanements, as well as physical improvements to the Airport such as lengthening the runway. The California Court of Appeal upheld the Town’s CEQA compliance in 2005
This Project also involves remodeling the existing 5,000-square foot (SF) maintenance building at the Airport for use as a 5,000-square foot (SF) passenger terminal. The passenger terminal would contain Transportation Security Administration (TSA) facilities, and may include baggage handling, customer services, rental cars, and food services within the renovated structure. No new facilities would be constructed as part of the proposed Project. However, the interior and exterior of the existing 5,000-square foot (SF) maintenance building would be remodeled for use as a passenger terminal. Collectively, the reinitiation of regularly scheduled commercial air service and the renovation of the existing maintenance building for use as a passenger terminal, constitute the proposed Project for this analysis.
The Town believes the Project may be exempt from CEQA, because much greater operational impacts have already been studied in a series of certified EIRs and there is only minor new construction proposed. However, to be conservative, and to provide for the fullest public disclosure and participation, the Town is preparing this Initial Study/Mitigated Negative Declaration.
The Town also desires, however, to prepare this further environmental review to document and analyze the potential impacts of any changes in the Project, as compared to the proposal that the 2002 Supplement analyzed, and any changes in the circumstances surrounding the Project. Accordingly, this Initial Study/Mitigated Negative Declaration addresses the direct, indirect, and cumulative environmental effects of the Project, as proposed.
1 Town of Mammoth Lakes, Final Supplement to Subsequent Environmental Impact Report, March 2002. State Clearinghouse No. 2000-034005.
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1.1 STATUTORY AUTHORITY AND REQUIREMENTS
In accordance with the California Environmental Quality Act (Public Resources Code Sections 21000-21177) and pursuant to Section 15063 of Title 14 of the California Code of Regulations (CCR) (CEQA Guideline 15063), the Town, acting as Lead Agency, is required to prepare an Initial Study to determine whether the proposed Project may have a potentially significant environmental impact, with or without mitigation. If the Lead Agency finds that there is no substantial evidence to support a fair argument that the Project, either as proposed or as modified to include the mitigation measures identified in the Initial Study, may cause a significant effect on the environment, the Lead Agency shall find that the proposed Project would not have a significant effect on the environment and shall prepare a Negative Declaration (or Mitigated Negative Declaration) for that project. Such determination can be made only if “there is no substantial evidence in light of the whole record before the Lead Agency” to support a fair argument that unavoidable significant impacts may occur. (Public Resources Code Section 21080[c]).
This documentation and analysis, which the Town would approve and/or certify before approving the proposed project, is intended as an informational document to provide an environmental basis for subsequent discretionary actions upon the Project, and to provide public disclosure of, and the opportunity for public discussion of, the potential impacts of the Project and proposed mitigation measures, if any. However, the resulting documentation is not a policy document, and its approval and/or certification neither presupposes nor mandates any actions on the part of those agencies from whom permits and other discretionary approvals would be required.
This Initial Study/Mitigated Negative Declaration is based on the Environmental Impact Report and Environmental Assessment Mammoth/June Lakes Airport Land Use Plan (1986 EIR/EA)2, the Mammoth Lakes Airport Expansion, Subsequent Environmental Impact Report and Updated Environmental Assessment (1997 Subsequent EIR)3, and the 2002 Supplement in that it: (a) relies on information and analysis presented in those documents, and (b) focuses its analysis on changes to the project or the surrounding circumstances that may have occurred, since the Town certified the 2002 Supplement. Accordingly, this Initial Study/Mitigated Negative Declaration is prepared consistent with CEQA Guidelines 15162 through 15163, which govern follow-up environmental review. This Initial Study/Mitigated Negative Declaration also relies on information in the Draft Environmental Impact Statement Request For Operations Specifications Amendment By Horizon Air to Provide Scheduled Air Service to Mammoth Yosemite Airport (November 2007) (2007 Draft EIS). Because that is a NEPA document, and this is a CEQA document, this document does not rely on the conclusions or standards of significance used in the NEPA document.
1.2 PURPOSE
Section 15063 of the CEQA Guidelines identifies specific disclosure requirements for an Initial Study. Pursuant to those requirements, an Initial Study shall include:
2 Mono County Airport Land Use Commission, Environmental Impact Report and Environmental Assessment Mammoth/June Lakes Airport Land Use Plan, July 1986. State Clearinghouse No. 86060901.
3 Town of Mammoth Lakes, Mammoth Lakes Airport Expansion, Subsequent Environmental Impact Report and Updated Environmental Assessment, 1997. State Clearinghouse No. 96112089.
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A description of the project, including the location of the project;
Identification of the environmental setting;
Identification of environmental effects by use of a checklist, matrix, or other method, provided that entries on a checklist or other form are briefly explained to indicate that there is some evidence to support the entries;
Discussion of ways to mitigate significant effects identified, if any;
Examination of whether the project is compatible with existing zoning, plans, and other applicable land use controls; and
The name(s) of the person(s) who prepared or participated in the preparation of the Initial Study.
Section 15162, Subsequent EIRs and Negative Declarations, of the CEQA Guidelines, discusses the three situations in which preparation of a subsequent EIR or negative declaration may be appropriate.
(a) When an EIR has been certified or a negative declaration adopted for a project, no subsequent EIR shall be prepared for that project unless the lead agency determines, on the basis of substantial evidence in the light of the whole record, one or more of the following:
(1) Substantial changes are proposed in the project, which will require major revisions of the previous EIR or negative declaration due to the involvement of new significant environmental effects or a substantial increase in the severity of previously identified significant effects;
(2) Substantial changes occur with respect to the circumstances under which the project is undertaken which will require major revisions of the previous EIR or Negative Declaration due to the involvement of new significant environmental effects or a substantial increase in the severity of previously identified significant effects; or
(3) New information of substantial importance, which was not known and could not have been known with the exercise of reasonable diligence at the time the previous EIR was certified as complete or the Negative Declaration was adopted, shows any of the following:
(A) The project will have one or more significant effects not discussed in the previous EIR or negative declaration;
(B) Significant effects previously examined will be substantially more severe than shown in the previous EIR;
(C) Mitigation measures or alternatives previously found not to be feasible would in fact be feasible, and would substantially reduce one or more significant effects of the project, but the project
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proponents decline to adopt the mitigation measure or alternative; or
(D) Mitigation measures or alternatives which are considerably different from those analyzed in the previous EIR would substantially reduce one or more significant effects on the environment, but the project proponents decline to adopt the mitigation measure or alternative.
(b) If changes to a project or its circumstances occur or new information becomes available after adoption of a negative declaration, the lead agency shall prepare a subsequent EIR if required under subdivision (a). Otherwise the lead agency shall determine whether to prepare a subsequent negative declaration, an addendum, or no further documentation.
(c) Once a project has been approved, the lead agency's role in project approval is completed, unless further discretionary approval on that project is required. Information appearing after an approval does not require reopening of that approval. If after the project is approved, any of the conditions described in subdivision (a) occurs, a subsequent EIR or negative declaration shall only be prepared by the public agency, which grants the next discretionary approval for the project, if any. In this situation no other responsible agency shall grant an approval for the project until the subsequent EIR has been certified or subsequent negative declaration adopted.
(d) A subsequent EIR or subsequent negative declaration shall be given the same notice and public review as required under Section 15087 or Section 15072. A subsequent EIR or negative declaration shall state where the previous document is available and can be reviewed.
Section 15163, Supplement to an EIR, of the CEQA Guidelines, provides the interpretations on how to handle public notice, public review, and circulation of additional environmental review.
(a) The Lead or Responsible Agency may choose to prepare a supplement to an EIR rather than a subsequent EIR if:
(1) Any of the conditions described in Section 15162 would require the preparation of a subsequent EIR, and
(2) Only minor additions or changes would be necessary to make the previous EIR adequately apply to the project in the changed situation.
(b) The supplement to the EIR need contain only the information necessary to make the previous EIR adequate for the project as revised.
(c) A supplement to an EIR shall be given the same kind of notice and public review as is given to a draft EIR under Section 15087.
(d) A supplement to an EIR may be circulated by itself without recirculating the previous draft or final EIR.
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(e) When the agency decides whether to approve the project, the decision-making body shall consider the previous EIR as revised by the supplemental EIR. A finding under Section 15091 shall be made for each significant effect shown in the previous EIR as revised.
As explained below, the Town has concluded that a Subsequent Initial Study/Mitigated Negative Declaration is appropriate, pursuant to Guideline 15162. The 2002 Supplement evaluated the potential impacts of the Mammoth Yosemite Airport Expansion project (2002 Project). The 2002 Project assessed involved 333,000 annual enplanements and 23,650 annual aircraft operations by 757-type aircraft, as well as various physical improvements to the Airport, including runway extension and widening, new fencing, and a new 25,000-SF passenger terminal, among others. The Town certified the 2002 Supplement on November 6, 2002. Subsequently, opponents of commercial air service unsuccessfully sought in the Superior Court a writ of mandate to compel the Town to vacate its certification of the report. The decision was appealed and the Court of Appeal in 2005 affirmed the Superior Court decision upholding the 2002 Supplement. Subsequent to the certification in 2002 and the appeal in 2005, the Town withdrew its proposal for the 2002 Project from consideration by the Federal Aviation Administration (FAA).
The current Project considers 67,168 annual enplanements and 17,482 annual aircraft operations with Bombadier de Havilland Canada (DHC) 8-402 (Q400 Dash 8) aircraft; however, no new construction would occur, other than the interior remodel of the existing maintenance building for use as a terminal. Comparatively, the current Project represents approximately 80 percent fewer enplanements and approximately 26 percent fewer aircraft operations, than the project analyzed in the 2002 Supplement.
This Initial Study/Mitigated Negative Declaration is based on, and supplements the analyses in prior EIRs prepared for Airport expansion; (refer to Section 1.3, Reference Documents) and concentrates its analysis on the issues specific to the terminal remodeling and Horizon Air’s proposed scheduled commercial air service, and particularly the changes between the proposed Project and the proposal analyzed in the 2002 Supplement, and any changes in the surrounding circumstances that may have occurred since that time. Additionally, the analysis in this Initial Study/Mitigated Negative Declaration will focus on any potential impacts of the proposed Project that may not have been examined in the 2002 Supplement, including, but not limited to, potential climate change impacts.
1.3 REFERENCE DOCUMENTS
The documents described below were utilized during preparation of this Initial Study/ Mitigated Negative Declaration. They are available for review at the Town of Mammoth Lakes Community Development Department located at 437 Old Mammoth Road, Suite R, Mammoth Lakes, California 93546.
Town of Mammoth Lakes General Plan 2007 (August 2007) (2007 General Plan). The Town of Mammoth Lakes Council adopted the 2007 General Plan on August 15, 2007. The 2007 General Plan establishes standards, guidelines, and priorities that define the Mammoth community now and for the future. The 2007 General Plan is organized by elements. Each element is introduced with an explanation of the intent of the goals, policies, and actions within that element. The 2007 General Plan contains the following elements:
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- Economy; - Arts, Culture, Heritage, and Natural History; - Community Design; - Neighborhood and District Character; - Land Use; - Mobility; - Resources Management and Conservation; and - Public Health and Safety.
It is noted that the Housing and Noise Elements were not updated as part of the 2007 General Plan. Additionally, the Parks and Recreation Element was not updated, although the 2007 General Plan includes a Parks, Open Space, and Recreation Chapter that provides updated goals and policies.
The 2007 General Plan was used in the preparation of this Initial Study/Mitigated Negative Declaration as a supporting policy and general background document that provides a description of the Town, its plans for future growth, and constraints on future growth in regards to cumulative analysis.
Town of Mammoth Lakes 2005 General Plan Update Final Program Environmental Impact Report (May 2007) (State Clearinghouse No. [SCH#] 2003042155) (GPEIR). The GPEIR evaluates the impacts associated with the 2007 General Plan. The GPEIR was prepared as a Program EIR, intended to facilitate consideration of broad policy directions, program-level alternatives, and mitigation measures consistent with the level of detail provided in the 2007 General Plan. The GPEIR concluded significant and unavoidable impacts regarding aesthetics, air quality, biological resources, public safety and hazards, noise, public services and utilities, and recreation. The GPEIR was used in the preparation of this Initial Study/Mitigated Negative Declaration as a supporting technical document that provided a description of the environmental setting and environmental impact conclusions.
Town of Mammoth Lakes Municipal Code. The Town of Mammoth Lakes Municipal Code (Code) consists of the Town’s regulatory, penal, and administrative ordinances. It is the method used by the Town to implement control of land uses, in accordance with General Plan goals and policies. Title 17 of the Code, Zoning, identifies land uses permitted and prohibited according to the zoning category of particular parcels. The Buildings and Construction Ordinance (Title 15 of the Code) specifies rules and regulations for construction, alteration, and building for uses of human habitation. Subdivisions are regulated under separate ordinances not contained within the Code. The Code was used in the preparation of this Initial Study/Mitigated Negative Declaration as a supporting technical document that provided development standards and guidelines, which may serve to avoid or lessen potential impacts.
Environmental Impact Report and Environmental Assessment Mammoth/June Lakes Airport Land Use Plan (July 1986) (SCH# 86060901) (1986 EIR/EA). This document was prepared by the Mono County Airport Land Use Commission (ALUC) to evaluate an airfield improvement program initiated by Mono County in 1983. The program partially relied upon funds to be received under the Airport Improvement Program, thus, required environmental review under both CEQA and National Environmental Policy Act (NEPA). The FAA was the designated federal lead agency. The Mono County Board of Supervisors certified this document in 1986.
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The project evaluated in the 1986 EIR/EA included an Airport Land Use Plan (ALUP) for the Airport and creation of an Airport Development District (ADD) for the Airport and surrounding land. The ADD planned developments included the continuation of improvements contemplated under the 1978 Mammoth/June Lake Airport Master Plan including the construction of a runway 7,000 feet in length by 100 feet in width, a 5,000 foot by 100 foot cross wind runway, additional taxiways, and additional aircraft support facilities, a new passenger terminal, an airport hotel, a 120-acre golf course, and extensive infrastructure improvements. The ADD also planned light industrial, manufacturing, warehousing, and similar economic development uses and, potentially, low intensity recreational uses. The 1986 EIR/EA evaluated 310,000 annual enplanements and 30,000 annual aircraft operations. Under the ALUP, land use policies were developed to protect public welfare and the safety of aircraft operations including policies regarding Airport safety zones, overflight zones and traffic patterns, height restrictions, and noise.
The key environmental topics evaluated in the 1986 EIR/EA included:
- Soils/land transformation; - Geologic/volcanic hazards; - Hydrology/water resources; - Water quality; - Mineral/energy resources; - Air quality; - Visual/aesthetic resources; - Biological resources; Archaeological/cultural resources; - Regional planning and population; - Employment and economic development; - Traffic and transportation; - Noise; - Safety and welfare; - Cumulative impacts; and - Other CEQA-required topics.
The 1986 EIR/EA was used in the preparation of this Initial Study/Mitigated Negative Declaration as a supporting technical document that provides a description of the environmental setting and environmental impact conclusions.
Mammoth Lakes Airport Expansion, Subsequent Environmental Impact Report and Updated Environmental Assessment (SCH# 96112089) (1997 Subsequent EIR). The Town prepared this combined environmental review document that was a Subsequent EIR for purposes of CEQA and an EA for purposes of NEPA, supplementing the 1986 EIR/EA as described in CEQA Guideline 15163. The 1997 Subsequent EIR evaluated environmental issues relative to changes in the project and substantial new information or changes in conditions since 1986. The Town certified this document in March 1997.
The Airport development reviewed in the 1997 Subsequent EIR included both airside and landside developments by a private developer. Airside improvements included:
- Extension of the current Runway 9-27 from 7,000 feet to 9,000 feet; - Strengthening the runway and associated taxiways to accommodate air carrier aircraft;
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- Construction of up to approximately 135 private and public use hangars; - An aviation fuel storage complex; and - Facilities for the operation of a fixed base operator (FBO).
The crosswind runway and the 120-acre golf course were eliminated from the originally proposed project. Landside development included a hotel/condominium complex, retail development, a restaurant complex and a recreational vehicle park. The 1997 Subsequent EIR evaluated 125,000 annual enplanements and 34,000 annual aircraft operations. The 1997 Subsequent EIR also included evaluation of the right to construct an access road from Benton Crossing Road to the Airport and signage on Town property along U.S. Highway 395.
The key environmental issues evaluated in the 1997 Subsequent EIR included:
- Noise; - Special-status species and wetlands; - Cultural resources; - Airport facilities; - Drainage; - Airport land use planning; and - Additional visual impacts.
The 1997 Subsequent EIR was used in the preparation of this Initial Study/Mitigated Negative Declaration as a supporting technical document that provided a description of the environmental setting and environmental impact conclusions.
Mammoth Yosemite Airport Expansion Project Final Environmental Assessment (December 2000) (2000 EA). The 2000 EA was prepared for the proposed runway expansion under NEPA guidelines. The document was prepared to provide the community full disclosure of the proposed improvements and potential environmental impacts of the development alternatives. This development differed from past development plans principally because it involved less land disturbance. The plan proposed to extend the runway from 7,000 feet to 8,200 feet rather than the previously approved length of 9,000 feet. The proposal also included widening the runway by 50 feet on the south side (total width of 150 feet). The FAA issued a Finding of No Significant Impact (FONSI) for the proposal in December 2000.
The 2000 EA was used in the preparation of this Initial Study/Mitigated Negative Declaration as a supporting technical document that provided a description of the environmental setting.
Final Supplement to Subsequent Environmental Impact Report Mammoth Yosemite Airport Expansion Project Mammoth Yosemite Airport (March 2002) (SCH# 2000- 034005) (2002 Supplement). The 2002 Supplement was prepared by the Town to review the environmental effects of proposed changes to the previously approved plans for expansion of the Airport. The 2002 Supplement evaluated 333,000 annual enplanements and 23,650 annual aircraft operations. The primary proposed changes to the Airport under consideration in the 2002 Supplement included:
- Extend the runway by 1,200 feet (from 7,000 feet to 8,200 feet); the 1986 and 1997 proposals included a runway extension of 2,000 feet;
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- Widen the runway by 50 feet (from 100 feet to 150 feet); the 1986 EIR/EA and 1997 Subsequent EIR proposals retained the runway width of 100 feet; - Replace the existing 4.8-foot barbed wire fence with an 8.0-foot chain link security fence; the 1986 EIR/EA and 1997 Subsequent EIR proposals did not involve replacing the perimeter security fence; - Construct a new package wastewater treatment plant; the 1986 EIR/EA and 1997 Subsequent EIR proposals included a new leach field; and - Relocate/replace the Green Church; the 1986 EIR/EA and 1997 Subsequent EIR proposals did involve relocating/replacing Green Church.
Prior approvals and environmental documentation had allowed for lengthening of the runway to 9,000 feet to accommodate narrow body air carrier jet aircraft. These approvals were in place since 1978. The major change with this proposal involved widening the runway to meet the operational and safety requirements of many air carriers. The Town certified this document in November 6, 2002.
As discussed in Section 1.2, Purpose, this Initial Study/Mitigated Negative Declaration is being prepared to assess the current Regional Air Service Project, based upon the analysis contained in the 2002 Supplement. This Initial Study/Mitigated Negative Declaration documents changes in the project and surrounding circumstances that have occurred since the Town certified 2002 Supplement. This Initial Study/Mitigated Negative Declaration relies on the general discussions from the broader 2002 Supplement, which provides a description of the environmental setting and environmental impact.
Draft Environmental Impact Statement Request For Operations Specifications Amendment By Horizon Air to Provide Scheduled Air Service to Mammoth Yosemite Airport (November 2007) (2007 Draft EIS). This document contains an environmental evaluation of the current proposal, as described in Section 2.0, Project Description, which is the subject of this Initial Study/Mitigated Negative Declaration. The FAA is preparing the EIS for purposes of NEPA.
The FAA published a Draft EIS for public review on November 16, 2008, and comments on the Draft EIS were due on January 11, 2008. Comments received as of the publication of this document have been considered in the preparation of this document. As permitted under CEQA, relevant data and information from the 2007 Draft EIS is relied on in this Initial Study/Mitigated Negative Declaration. The 2007 Draft EIS is being used as a technical reference, but because NEPA has different standards than CEQA, that document’s conclusions of significance or mitigation requirements are not binding on this document, and may not be applicable.
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2.0 PROJECT DESCRIPTION
2.1 PROJECT LOCATION AND SETTING
PROJECT LOCATION
The Town is located in the eastern side of the Sierra Nevada Range, in southwestern Mono County, California; refer to Exhibit 1, Regional Vicinity. The Airport is located approximately six miles east of the Town, in a remote area adjacent to U.S. Highway 395, between Hot Creek Hatchery Road and Benton Crossing Road; refer to Exhibit 2, Local Vicinity. The Airport’s field elevation is approximately 7,128 feet above mean sea level.
EXISTING SETTING AND CONDITIONS
Existing Airport
The Town is the owner and operator of the Airport, which predominantly serves general aviation aircraft, but also serves tourist and visitor charter flights. The Town holds a Class IV certificate from the FAA for the Airport. Under this classification, unscheduled air carrier operations can be provided using aircraft capable of carrying 30 or more passengers. The Airport has a single runway, designated as Runway 9-27, which is paved with asphalt and is 7,000 feet long by 100 feet wide; refer to Exhibit 3, Existing Airport Facilities. It should be noted that Airport is currently in the process of initiating a rehabilitation of the existing runway. This is the first time this work has been done on the runway since the 1970s, and this work is required at this time to comply with FAA requirements and to ensure safety for existing uses at the Airport. This project is funded by a grant from the Federal Aviation Administration (3-06-0146-17), and is not related to the proposed Project. A full parallel taxiway system, 50 feet in width, supports this runway. A Global Positioning System (GPS) non-precision instrument approach is available to Runway 9- 27. Apron and hangar facilities are available for both based and transient aircraft.
The Airport’s facilities accommodate commercial airlines, commuter airlines, and support/ maintenance for unscheduled operations. The Airport also accommodates general aviation aircraft activity including aircraft hangars and outdoor tiedowns. The Airport has six based aircraft and accommodates approximately 12,800 annual aircraft operations. Over the past 30 years, scheduled commercial service has been provided intermittently at the Airport, with the last service being provided during the winter seasons of 1992 and 1993. At the current time, there is no regularly scheduled commercial air service provided at the Airport.
Surrounding Land Uses
The existing land uses in the vicinity of the Airport are illustrated on Exhibit 4, Existing Land Use. Lands to the north, northwest, and south of the Airport are Federally-owned and within the Inyo National Forest. Lands to the northeast of the Airport are owned by the Bureau of Land Management (BLM) and are undeveloped. The Los Angeles Department of Water and Power (LADWP) own eastern portions of the Airport, including lands under a portion of the runway. The Town currently leases this land.
JN 10-106064 - 10 - March 14, 2008 80 89 NEVADA COUNTY Nevada City 20 Truckee 267 50 28 Grass Tahoe Valley City PLACER Carson LAKE City Colfax COUNTY TAHOE 80 89
193 South 88 NEVADA Lake 95 49 EL DORADO Tahoe COUNTY 50 395 Placerville 89 49 ALPINE COUNTY Coleville 88
16 AMADOR COUNTY Hawthorne Sutter 124 Creek Ione Jackson 26 4 CALAVERAS COUNTY 108 Bridgeport San 12 Andreas 49 26 167 Twain TUOLUMNE SAN Angels Harte COUNTY MONO 95 JOAQUIN Camp LAKE 6 COUNTY Lee Vining 4 Sonora 120
108 120 MONO 120 120 COUNTY Oakdale June Lake STANISLAUS Modesto COUNTY 49 Project 132 MARIPOSA COUNTY 6 Ceres Mammoth Site Lakes 99 41 395 Turlock Mariposa 59 49
140 Bishop 168 Atwater 140 Merced Oakhurst MADERA COUNTY Gustine MERCED 165 COUNTY Big Pine Los Chowchilla Banos
168 Madera 41 INYO COUNTY FRESNO 145 COUNTY 33 Independence Clovis Mendota 180 Fresno 395
99 Lone Pine 5 Reedley 63 245 Dinuba 136 SAN BENITO 201 198 COUNTY 43 Woodlake Three Rivers 145 190 Hanford TULARE 190 Lemoore COUNTY 269 Visalia Olancha
Tulare 137 Lindsay 41 KINGS COUNTY MONTEREY Coalinga COUNTY 198 65 Corcoran Porterville
NOT TO SCALE INITIAL STUDY/MITIGATED NEGATIVE DECLARATION MAMMOTH YOSEMITE AIRPORT REGIONAL AIR SERVICE Regional Vicinity 03/08 • JN 10-106064 Exhibit 1 Source: Thomas Bros. Map, 2006. - Project Site
NOT TO SCALE INITIAL STUDY/MITIGATED NEGATIVE DECLARATION MAMMOTH YOSEMITE AIRPORT REGIONAL AIR SERVICE Local Vicinity 03/08 • JN 10-106064 Exhibit 2 NOT TO SCALE INITIAL STUDY/MITIGATED NEGATIVE DECLARATION MAMMOTH YOSEMITE AIRPORT REGIONAL AIR SERVICE Existing Airport Facilities 03/08 • JN 10-106064 Exhibit 3 NOT TO SCALE INITIAL STUDY/MITIGATED NEGATIVE DECLARATION MAMMOTH YOSEMITE AIRPORT REGIONAL AIR SERVICE Existing Land Use 03/08 • JN 10-106064 Exhibit 4 Town of Mammoth Lakes Mammoth Yosemite Airport Regional Air Service Initial Study/Mitigated Negative Declaration
The Airport environs include open spaces used for agriculture, resource management areas of the U.S. Department of Agriculture - Forest Service (USDA-FS), LADWP, BLM, and recreation. Small parcels in close proximity to the Airport are used for industrial and public agency uses. Hot Creek is located on the western side of the Airport, with the abandoned Mammoth Lakes Elementary School and Sierra Quarry further west. Approximately one mile north of the Airport is Hot Creek Ranch, a privately-owned fishing camp and the Hot Creek Fish Hatchery. Also located north of the Airport, between the Airport and Hot Creek Ranch, is a USDA-FS gravel/borrow pit. To the east of the Whitmore Recreational Area is a BLM gravel pit area that is adjacent to U.S. Highway 395. The Sierra Nevada Aquatic Research Laboratory (SNARL) is located approximately one mile southeast of the Airport and south of U.S. Highway 395. This facility is part of the University of California Natural Reserve System that studies stream ecology. The building locally known as the “Green Church” (High Sierra Community Church) is located on the north side of U.S. Highway 395. However, this facility is now a part of the SNARL campus and is used exclusively for classes. Approximately two miles south of the Airport is the Convict Lake Recreation Area, which includes an Inyo National Forest Campground and other facilities. There are no residential areas in the immediate vicinity of the Airport.
2.2 PROJECT CHARACTERISTICS
This Initial Study/Mitigated Negative Declaration has been prepared to analyze potential environmental impacts of the terminal modifications and the changes to the proposed operations specifications related to the scheduled commercial air service into the Airport by Horizon Air. Horizon Air initially proposes to conduct two-daily flights from Los Angeles International Airport (LAX) to the Airport using their Bombardier DHC 8-402 (Q400 Dash 8) aircraft. The Q400 Dash 8 is part of the Bombardier Dash 8 family of turbo-propeller driven passenger aircraft. The Q400 Dash 8 can seat up to 78 people. Horizon Air has provided the FAA with a letter of intent to initiate winter ski season passenger service into the Airport in the winter of 2008-09.
Horizon Air is proposing to begin scheduled regional air carrier service to the Airport beginning in December 2008 with two flights per day from LAX during the winter ski season (approximately December to April). The Town has prepared and submitted to the FAA a forecast of future commercial aviation activity at the Airport. The FAA has reviewed and approved this forecast, which is discussed in greater detail below. Winter ski service is projected to increase to a maximum of eight flights per day by the year 2011. The aviation activity forecast for the Airport, also considers the addition of two flights per day during the summer months beginning in 2012.
No new facilities would be constructed as part of the proposed Project. However, the interior and exterior of the existing 5,000-square foot (SF) maintenance building would be remodeled for use as a passenger terminal. The passenger terminal would contain TSA facilities, and may include baggage handling, customer services, rental cars, and food services within the renovated structure; refer to Exhibit 5, Proposed Passenger Terminal Improvements. Restrooms and wash station facilities would be provided within the terminal. New gates would be added to the existing fence at the terminal to allow for passenger processing and access to the airfield from the terminal. No additional pavement or other ground-disturbing changes are proposed.
JN 10-106064 - 15 - March 14, 2008 Source: Van Sant Group; January 10, 2007.
NOT TO SCALE INITIAL STUDY/MITIGATED NEGATIVE DECLARATION MAMMOTH YOSEMITE AIRPORT REGIONAL AIR SERVICE Proposed Passenger Terminal Improvements 03/08 • JN 10-106064 Exhibit 5 Town of Mammoth Lakes Mammoth Yosemite Airport Regional Air Service Initial Study/Mitigated Negative Declaration
To summarize, the proposed changes to the Airport under consideration in this Initial Study/Mitigated Negative Declaration involve:
Commencement of scheduled commercial air service; Remodel the interior and exterior of the existing maintenance building for use as a passenger terminal; and Modify the existing fence at the existing maintenance building.
Table 2-1, Summary of Development Proposals, provides a comparative analysis of the current proposal and the Mammoth Yosemite Airport Expansion project (2002 Project) evaluated in the 2002 Supplement. The current Project considers 67,168 annual enplanements and 17,482 annual aircraft operations; however, no new construction or runway modification is proposed. Comparatively, the current Project represents approximately 80 percent fewer enplanements and approximately 26 percent fewer aircraft operations, than the project analyzed in the 2002 Supplement; refer to Table 2-1.
Table 2-1 Summary of Development Proposals
2002 Supplement Current Project Description Difference (Planned/Forecast)1 (Planned/Forecast)2 Runway Extension (Feet) +1,200 0 Runway Widening (Feet) +50 0 No changes to existing Runway Strengthening Yes No runways or taxiways. Taxiway Extension (Feet) +1,200 0 Taxiway Widening (Feet) +25 0 Taxiway Strengthening Yes No Hangars, Transient (Units) 103 0 No hangar Hangars, Transient (Units) 1353 0 construction. Terminal Construction (SF) 25,000 Remodel Existing No terminal Maintenance Building Construction (minor improvements only). Fencing (Feet) 8.0 (Chain Link) Modify No new fencing. Existing Fencing Enplanements (Passengers) 333,000 2009 = 20,214 2015 = 67,168 -265,832 (-80%) Aircraft Operations (Flights) 23,650 2009 = 14,249 2015 = 17,482 -6,168 (-26%) Parking (Spaces) 760 0 No new parking. Grading (Acres) 200 0 No grading. 1. Table 1, Mammoth Yosemite Airport – Airport Development Analysis, of the 2002 Supplement. 2. 2007 Draft EIS. 3. All are completed.
JN 10-106064 - 17 - March 14, 2008 Town of Mammoth Lakes Mammoth Yosemite Airport Regional Air Service Initial Study/Mitigated Negative Declaration
2.3 BACKGROUND AND HISTORY
The Town has owned and operated Mammoth Yosemite Airport, since 1992. The land area on which the Airport and its immediate surroundings is located was annexed into the Town in April 1995.
The Town is located at a considerable distance from any commercial service airport, with the closest being Reno/Tahoe International Airport at a distance of 170 miles. Currently, the majority of the Town’s visitors arrive by privately-owned automobiles, from the Los Angeles or Reno areas. Visitors from outside California and Nevada typically fly to Reno or Los Angeles and then travel by automobile to the Town.
Mono County is one of the most sparsely populated counties in California. According to the California Department of Finance, the County’s population as of January 2007 is an estimated 13,985 persons.4 While the County’s population is relatively small, the County is relatively large geographically, comprising nearly 2.0 million acres. The Town’s population, as of January 2007, is an estimated 7,560 persons.5 Approximately 54 percent of the County’s population is concentrated in Mammoth Lakes and nearby Long Valley communities. During the winter months, an average peak population of 34,264 (“People at One Time or PAOT”), which is over four times the permanent population, is normal.6
The County’s economy is heavily dependent upon tourism and resort recreation. Nearby tourist attractions include Yosemite National Park, Death Valley National Park, Mono Lake, June Lake, and Devil’s Postpile National Monument. It is estimated that nearly six million persons visit Yosemite and Death Valley National Parks annually with most of this visitation occurring during the summer months. Poor road conditions and closure of the main route into Yosemite from the east during the winter mean that most of these attractions are not accessible from Mammoth Lakes in the winter, when the initial air service would occur. The County provides numerous outdoor recreational activities in the warmer months, and an estimated 1.5 million tourists visit the Mammoth Lakes region annually during the summer. During the winter months, the region provides skiing and related recreational activities, generally concentrated in and around Mammoth Lakes. Skier visits may fluctuate based on weather and economic factors. During the early to mid-1980s, the Mammoth Mountain Ski Area (MMSA) was one of the most popular ski destinations in the country. In the 1985-1986 season, the MMSA received more than 1.5 million skier visits. By the 1998-1999 season, the MMSA received fewer than one million visits. The decline in MMSA’s tourism was attributed in part to the development of resort areas in Colorado, Utah, and elsewhere that emphasize guest services, including commercial and charter air access, while little had been done to make the Mammoth Mountain region a “destination mountain resort.”
In the late 1990s, a number of public and private projects commenced. Developers began investing in the area, creating new tourist accommodations, base villages, and retail areas. Private developers also constructed condominium units, a village center, and golf course expansion.7 Mammoth Mountain also added snow-making and other on-mountain
4 State of California, Department of Finance, E-5 Population and Housing Estimates for Cities, Counties and the State, 2001-2007, with 2000 Benchmark. Sacramento, California, May 2007.
5 Ibid.
6 Town of Mammoth Lakes, Final Program Environmental Impact Report for the Town of Mammoth Lakes 2005 General Plan Update, May 2007.
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improvements. Additionally, the Town invested in improvements, creating a commercial core with public facilities, pedestrian walkways, and other infrastructure. By 2003, MMSA began to experience over 1.3 million skier visits and in 2006 topped 1.4 million skier visits.
In order to sustain economic viability in the community, public and private interests, working to make the area into a destination resort and a stable year-round economy, have identified commercial air service as an integral component of their vision and began working to obtain FAA funding for improvements to the Airport. In 2000, the Town proposed modifications to the existing Airport development plans. These proposed modifications, in particular the widening of the runway, were primarily intended to permit air carrier aircraft up to the size of a Boeing 757- 200 to operate at the Airport. For purposes of CEQA, the Town prepared the 2002 Supplement, incorporating previous environmental reviews that were conducted in 1986 and 1997. The purpose of the 2002 Supplement was to analyze the proposed modifications to the 1997 Project, as described above, and analyze the impacts associated with an updated aviation demand forecast. The Town prepared and circulated a Draft 2002 Supplement. The Town also accepted and responded to comments, and conducted a hearing before the Town Council. The Town Council certified the 2002 Supplement but directed that minor changes be made to the Final 2002 Supplement. Subsequently, the Town certified the corrected 2002 Supplement and adopted an addendum to the 2002 Supplement. Following approval, the Sierra Club, National Parks Conservation Association, and Natural Resources Defense Council, unsuccessfully sought a writ of mandate to compel the Town to vacate its certification of the 2002 Supplement and project approval, contending that the 2002 Supplement did not adequately analyze the project’s growth-inducing impacts, cumulative impacts, project alternatives, and impacts on traffic, water supply, and air quality. The decision was appealed in 2005 and the Court of Appeal affirmed the trial court decision to deny the petition.
For purposes of NEPA, the FAA published a Draft EA for the Airport expansion described above in October 2000. A Final EA for the Airport expansion was published in December 2000. The FAA approved and adopted the Final EA and issued a FONSI on December 21, 2000. Following FAA’s issuance of the FONSI, supplemental information regarding the proposed expansion became available. On July 29, 2002, the FAA issued a Record of Decision (ROD) that reexamined the December 21, 2000 FONSI, and approved the Town’s proposed expansion plan for the Airport. Subsequent to the publication of FAA’s ROD, litigation was filed against the FAA in two civil cases in the United States District Court for the Northern District of California. On April 28, 2003, the Court issued an opinion that required FAA to prepare an EIS to further evaluate the Town’s proposed expansion project for the Airport.
In September 2003, the Town entered into a Memorandum of Understanding (MOU) with the FAA regarding preparation of an EIS for the same Airport improvements proposed in 2000. The Town subsequently withdrew their interest in pursuing the 2002 Project. Upon receipt of the Letter of Intent from Horizon Airlines, the FAA filed a new Notice of Intent (NOI) on July 26, 2006 to prepare an EIS for the Horizon Airlines request. The FAA released the Draft EIS for agency and public review (November 23, 2007 to January 11, 2008). The 2007 Draft EIS concludes that the proposed Airport improvements would have no significant impacts on any environmental category examined.
7 State of California, Department of Finance, E-5 Population and Housing Estimates for Cities, Counties and the State, 2001-2007, with 2000 Benchmark. Sacramento, California, May 2007.
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2.4 AGREEMENTS, PERMITS, AND APPROVALS
The Town of Mammoth Lakes approvals required for modification of the terminal and the recommencement of regularly-scheduled commercial air service include the following, among others:
Town of Mammoth Lakes Adoption or certification of an appropriate and legally adequate CEQA document; Approval of a construction contract; Authorization of funding for the proposed Project; Building Permit;
Others Long Valley Fire Protection District Development Review; Great Basin Unified Air Pollution Control District permits; and Mono County Health Department.
The FAA approvals required for implementation of the proposed Project would include the following, among others:
Amendment to Operations Specifications for Horizon Air (to permit scheduled commercial air service to the Airport using the Q400 Dash 8 aircraft); Town Application for Certificate Amendment; and Modifications to the Town MMH Airport Certification Manual.
These Federal approvals would rely on the 2007 Draft EIS, when it is completed.
JN 10-106064 - 20 - March 14, 2008 Town of Mammoth Lakes Mammoth Yosemite Airport Regional Air Service Initial Study/Mitigated Negative Declaration
3.0 INITIAL STUDY CHECKLIST
3.1 BACKGROUND
1. Project Title:
Mammoth Yosemite Airport Regional Air Service
2. Lead Agency Name and Address:
Town of Mammoth Lakes P.O. Box 1609 437 Old Mammoth Road, Suite R Mammoth Lakes, California 93546 3. Contact Person and Phone Number:
Ms. Karen Johnston Ray Jarvis Assistant Town Manager Public Works Director 760.934.8989, Ext. 228 760.934.8989 ext. 257
4. Project Location:
The Airport is located approximately 6.0 miles east of the Town, north of and adjacent to U.S. Highway 395, between Hot Creek Hatchery Road and Benton Crossing Road; refer to Section 2.1, Project Location and Setting.
5. Project Sponsor’s Name and Address:
Town of Mammoth Lakes
6. General Plan Designation:
The Airport property is designated Airport (A).
7. Zoning District:
The Airport property is zoned Airport (A) Zone.
8. Description of the Project:
Refer to Section 2.2, Project Characteristics.
9. Surrounding Land Uses and Setting:
Refer to Section 2.1, Project Location and Setting.
10. Other public agencies whose approval is required (e.g., permits, financing approval or participation agreement):
Refer to Section 2.4, Agreements, Permits, and Approvals.
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3.2 ENVIRONMENTAL FACTORS POTENTIALLY AFFECTED
The environmental factors checked below would be potentially affected by this project, involving at least one impact that is a “Potentially Significant Impact” or “Potentially Significant Unless Mitigated,” as indicated by the checklist on the following pages.
Aesthetics Land Use and Planning Agriculture Resources Mineral Resources Air Quality Noise Biological Resources Population and Housing Cultural Resources Public Services Geology and Soils Recreation Hazards & Hazardous Materials Transportation/Traffic Hydrology & Water Quality Utilities & Service Systems Mandatory Findings of Significance (If Necessary)
3.3 LEAD AGENCY DETERMINATION
On the basis of this initial evaluation:
I find that the proposed use COULD NOT have a significant effect on the environment, and a NEGATIVE DECLARATION will be prepared.
I find that although the proposal could have a significant effect on the environment, there will not be a significant effect in this case because the mitigation measures described in Section 5.0, Inventory of Mitigation Measures, have been added. A NEGATIVE DECLARATION will be prepared.
I find that the proposal MAY have a significant effect on the environment, and an ENVIRONMENTAL IMPACT REPORT is required.
I find that the proposal MAY have a significant effect(s) on the environment, but at least one effect 1) has been adequately analyzed in an earlier document pursuant to applicable legal standards, and 2) has been addressed by mitigation measures based on the earlier analysis as described on attached sheets, if the effect is a “potentially significant impact” or “potentially significant unless mitigated.” An ENVIRONMENTAL IMPACT REPORT is required, but it must analyze only the effects that remain to be _____ addressed.
Town of Mammoth Lakes
Signature Agency
Karen Johnston, Assistant Town Manager March 14, 2008 Printed Name and Title Date
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3.4 EVALUATION OF ENVIRONMENTAL IMPACTS
This section analyzes the potential environmental impacts associated with the proposed Project. The issue areas evaluated in this Initial Study include:
Aesthetics • Land Use and Planning Agriculture Resources • Mineral Resources Air Quality • Noise Biological Resources • Population and Housing Cultural Resources • Public Services Geology and Soils • Recreation Hazards and Hazardous Materials • Transportation/Traffic Hydrology and Water Quality • Utilities and Service Systems
The environmental analysis in this section is patterned after the Initial Study Checklist recommended by the CEQA Guidelines, Appendix G, as amended, and used by the Town in its environmental review process. For the preliminary environmental assessment undertaken as part of this Initial Study’s preparation, a determination that there is a potential for significant effects indicates the need to more fully analyze the development’s impacts and to identify mitigation.
For the evaluation of potential impacts, the questions in the Initial Study Checklist are stated and an answer is provided according to the analysis undertaken as part of the Initial Study. The analysis considers the long-term, direct, indirect, and cumulative impacts of the development. To each question, there are four possible responses:
No Impact. The development will not have any measurable environmental impact on the environment.
Less Than Significant Impact. The development will have the potential for impacting the environment, although this impact will be below established thresholds that are considered to be significant.
Less Than Significant With Mitigation Incorporated. The development will have the potential to generate impacts, which may be considered as a significant effect on the environment, although mitigation measures or changes to the development’s physical or operational characteristics can reduce these impacts to levels that are less than significant.
Potentially Significant Impact. The development could have impacts, which may be considered significant, and therefore additional analysis is required to identify mitigation measures that could reduce potentially significant impacts to less than significant levels.
Where potential impacts are anticipated to be significant, mitigation measures will be required, so that impacts may be avoided or reduced to insignificant levels.
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Less Than Potentially Less Than Significant No Significant With Significant Impact Impact Mitigation Impact Incorporated 1. AESTHETICS. Would the Project: a. Have a substantial adverse effect on a scenic vista? b. Substantially damage scenic resources, including, but not limited to, trees, rock outcroppings, and historic buildings within a state scenic highway? c. Substantially degrade the existing visual character or quality of the site and its surroundings? d. Create a new source of substantial light or glare, which would adversely affect day or nighttime views in the area? 2. AGRICULTURE RESOURCES. In determining whether impacts to agricultural resources are significant environmental effects, lead agencies may refer to the California Agricultural Land Evaluation and Site Assessment Model (1997) prepared by the California Department of Conservation as an optional model to use in assessing impacts on agriculture and farmland. Would the Project: a. Convert Prime Farmland, Unique Farmland, or Farmland of Statewide Importance (Farmland), as shown on the maps prepared pursuant to the Farmland Mapping and Monitoring Program of the California Resources Agency, to non- agricultural use? b. Conflict with existing zoning for agricultural use, or a Williamson Act contract? c. Involve other changes in the existing environment, which, due to their location or nature, could result in conversion of farmland to non-agricultural use? 3. AIR QUALITY. Where available, the significance criteria established by the applicable air quality management or air pollution control district may be relied upon to make the following determinations. Would the Project: a. Conflict with or obstruct implementation of the applicable air quality plan? b. Violate any air quality standard or contribute substantially to an existing or projected air quality violation? c. Result in a cumulatively considerable net increase of any criteria pollutant for which the project region is non-attainment under an applicable federal or state ambient air quality standard (including releasing emissions which exceed quantitative thresholds for ozone precursors)? d. Expose sensitive receptors to substantial pollutant concentrations? e. Create objectionable odors affecting a substantial number of people?
JN 10-106064 - 24 - March 14, 2008 Town of Mammoth Lakes Mammoth Yosemite Airport Regional Air Service Initial Study/Mitigated Negative Declaration
Less Than Potentially Less Than Significant No Significant With Significant Impact Impact Mitigation Impact Incorporated 4. BIOLOGICAL RESOURCES. Would the Project: a. Have a substantial adverse effect, either directly or through habitat modifications, on any species identified as a candidate, sensitive, or special status species in local or regional plans, policies, or regulations, or by the California Department of Fish and Game or U.S. Fish and Wildlife Service? b. Have a substantial adverse effect on any riparian habitat or other sensitive natural community identified in local or regional plans, policies, or regulations, or by the California Department of Fish and Game or U.S. Fish and Wildlife Service? c. Have a substantial adverse effect on federally protected wetlands as defined by Section 404 of the Clean Water Act (including, but not limited to, marsh, vernal pool, coastal, etc.) through direct removal, filling, hydrological interruption, or other means? d. Interfere substantially with the movement of any native resident or migratory fish or wildlife species or with established native resident or migratory wildlife corridors, or impede the use of native wildlife nursery sites? e. Conflict with any local policies or ordinances protecting biological resources, such as a tree preservation policy or ordinance? f. Conflict with the provisions of an adopted Habitat Conservation Plan, Natural Community Conservation Plan, or other approved local, regional, or state habitat conservation plan? 5. CULTURAL RESOURCES. Would the Project: a. Cause a substantial adverse change in the significance of a historical resource as defined in CEQA Guidelines §15064.5? b. Cause a substantial adverse change in the significance of an archaeological resource pursuant to CEQA Guidelines §15064.5? c. Directly or indirectly destroy a unique paleontological resource or site or unique geologic feature? d. Disturb any human remains, including those interred outside of formal cemeteries? 6. GEOLOGY AND SOILS. Would the Project: a. Expose people or structures to potential substantial adverse effects, including the risk of loss, injury, or death involving:
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Less Than Potentially Less Than Significant No Significant With Significant Impact Impact Mitigation Impact Incorporated 1) Rupture of a known earthquake fault, as delineated on the most recent Alquist- Priolo Earthquake Fault Zoning Map issued by the State Geologist for the area or based on other substantial evidence of a known fault? Refer to Division of Mines and Geology Special Publication 42. 2) Strong seismic ground shaking? 3) Seismic-related ground failure, including liquefaction? 4) Landslides? b. Result in substantial soil erosion or the loss of topsoil? c. Be located on a geologic unit or soil that is unstable, or that would become unstable as a result of the project, and potentially result in on- or off-site landslide, lateral spreading, subsidence, liquefaction or collapse? d. Be located on expansive soil, as defined in Table 18-1-B of the Uniform Building Code (1994), creating substantial risks to life or property? e. Have soils incapable of adequately supporting the use of septic tanks or alternative wastewater disposal systems where sewers are not available for the disposal of wastewater? 7. HAZARDS AND HAZARDOUS MATERIALS. Would the Project: a. Create a significant hazard to the public or the environment through the routine transport, use, or disposal of hazardous materials? b. Create a significant hazard to the public or the environment through reasonably foreseeable upset and accident conditions involving the release of hazardous materials into the environment? c. Emit hazardous emissions or handle hazardous or acutely hazardous materials, substances, or waste within one-quarter mile of an existing or proposed school? d. Be located on a site, which is included on a list of hazardous materials sites compiled pursuant to Government Code Section 65962.5, and, as a result, would it create a significant hazard to the public or the environment? e. For a project located within an airport land use plan or, where such a plan has not been adopted, within two miles of a public airport or public use airport, would the project result in a safety hazard for people residing or working in the project area?
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Less Than Potentially Less Than Significant No Significant With Significant Impact Impact Mitigation Impact Incorporated f. For a project within the vicinity of a private airstrip, would the project result in a safety hazard for people residing or working in the project area? g. Impair implementation of or physically interfere with an adopted emergency response plan or emergency evacuation plan? h. Expose people or structures to a significant risk of loss, injury or death involving wildland fires, including where wildlands are adjacent to urbanized areas or where residences are intermixed with wildlands? 8. HYDROLOGY AND WATER QUALITY. Would the Project: a. Violate any water quality standards or waste discharge requirements? b. Substantially deplete groundwater supplies or interfere substantially with groundwater recharge such that there would be a net deficit in aquifer volume or a lowering of the local groundwater table level (e.g., the production rate of pre-existing nearby wells would drop to a level which would not support existing land uses or planned uses for which permits have been granted)? c. Substantially alter the existing drainage pattern of the site or area, including through the alteration of the course of stream or river, in a manner, which would result in substantial erosion or siltation on- or off-site? d. Substantially alter the existing drainage pattern of the site or area, including through the alteration of the course of a stream or river, or substantially increase the rate or amount of surface runoff in a manner, which would result in flooding on- or off-site? e. Create or contribute runoff water which would exceed the capacity of existing or planned stormwater drainage systems or provide substantial additional sources of polluted runoff? f. Otherwise substantially degrade water quality? g. Place housing within a 100-year flood hazard area as mapped on a federal Flood Hazard Boundary or Flood Insurance Rate Map or other flood hazard delineation map? h. Place within a 100-year flood hazard area structures, which would impede or redirect flood flows?
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Less Than Potentially Less Than Significant No Significant With Significant Impact Impact Mitigation Impact Incorporated i. Expose people or structures to a significant risk of loss, injury or death involving flooding, including flooding as a result of the failure of a levee or dam? j. Inundation by seiche, tsunami, or mudflow? 9. LAND USE AND PLANNING. Would the Project: a. Physically divide an established community? b. Conflict with any applicable land use plan, policy, or regulation of an agency with jurisdiction over the project (including, but not limited to the general plan, specific plan, local coastal program, or zoning ordinance) adopted for the purpose of avoiding or mitigating an environmental effect? c. Conflict with any applicable habitat conservation plan or natural community conservation plan? 10. MINERAL RESOURCES. Would the Project: a. Result in the loss of availability of a known mineral resource that would be of value to the region and the residents of the state? b. Result in the loss of availability of a locally important mineral resource recovery site delineated on a local general plan, specific plan or other land use plan? 11. NOISE. Would the Project result in: a. Exposure of persons to, or generation of, noise levels in excess of standards established in the local general plan or noise ordinance, or applicable standards of other agencies? b. Exposure of persons to or generation of excessive groundborne vibration or groundborne noise levels? c. A substantial permanent increase in ambient noise levels in the project vicinity above levels existing without the project? d. A substantial temporary or periodic increase in ambient noise levels in the project vicinity above levels existing without the project? e. For a project located within an airport land use plan or, where such a plan has not been adopted, within two miles of a public airport or public use airport, would the project expose people residing or working in the project area to excessive noise levels? f. For a project within the vicinity of a private airstrip, would the project expose people residing or working in the project area to excessive noise levels?
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Less Than Potentially Less Than Significant No Significant With Significant Impact Impact Mitigation Impact Incorporated 12. POPULATION AND HOUSING. Would the Project: a. Induce substantial population growth in an area, either directly (for example, by proposing new homes and businesses) or indirectly (for example, through extension of roads or other infrastructure)? b. Displace substantial numbers of existing housing, necessitating the construction of replacement housing elsewhere? c. Displace substantial numbers of people, necessitating the construction of replacement housing elsewhere? 13. PUBLIC SERVICES. a. Would the project result in substantial adverse physical impacts associated with the provision of new or physically altered governmental facilities, need for new or physically altered governmental facilities, the construction of
which could cause significant environmental impacts, in order to maintain acceptable service ratios, response times or other performance objectives for any of the public services: 1) Fire protection? 2) Police protection? 3) Schools? 4) Parks? 5) Other public facilities? 14. RECREATION. a. Would the project increase the use of existing neighborhood and regional parks or other recreational facilities such that substantial physical deterioration of the facility would occur or be accelerated? b. Does the project include recreational facilities or require the construction or expansion of recreational facilities, which might have an adverse physical effect on the environment? 15. TRANSPORTATION/TRAFFIC. Would the Project: a. Cause an increase in traffic, which is substantial in relation to the existing traffic load and capacity of the street system (i.e., result in a substantial increase in either the number of vehicle trips, the volume to capacity ratio on roads, or congestion at intersections)? b. Exceed, either individually or cumulatively, a level of service standard established by the county congestion management agency for designated roads or highways?
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Less Than Potentially Less Than Significant No Significant With Significant Impact Impact Mitigation Impact Incorporated c. Result in a change in air traffic patterns, including either an increase in traffic levels or a change in location that results in substantial safety risks? d. Substantially increase hazards due to a design feature (e.g., sharp curves or dangerous intersections) or incompatible uses (e.g., farm equipment)? e. Result in inadequate emergency access? f. Result in inadequate parking capacity? g. Conflict with adopted policies, plans, or programs supporting alternative transportation (e.g., bus turnouts, bicycle racks)? 16. UTILITIES AND SERVICE SYSTEMS. Would the Project: a. Exceed wastewater treatment requirements of the applicable Regional Water Quality Control Board? b. Require or result in the construction of new water or wastewater treatment facilities or expansion of existing facilities, the construction of which could cause significant environmental effects? c. Require or result in the construction of new storm water drainage facilities or expansion of existing facilities, the construction of which could cause significant environmental effects? d. Have sufficient water supplies available to serve the project from existing entitlements and resources, or are new or expanded entitlements needed? e. Result in a determination by the wastewater treatment provider, which serves or may serve the project that it has adequate capacity to serve the project’s projected demand in addition to the provider’s existing commitments? f. Be served by a landfill with sufficient permitted capacity to accommodate the project’s solid waste disposal needs? g. Comply with federal, state, and local statutes and regulations related to solid waste?
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Less Than Potentially Less Than Significant No Significant With Significant Impact Impact Mitigation Impact Incorporated 17. MANDATORY FINDINGS OF SIGNIFICANCE. a. Does the project have the potential to degrade the quality of the environment, substantially reduce the habitat of a fish or wildlife species, cause a fish or wildlife population to drop below self-sustaining levels, threaten to eliminate a plant or animal community, reduce the number or restrict the range of a rare or endangered plant or animal or eliminate important examples of the major periods of California history or prehistory? b. Does the project have impacts that are individually limited, but cumulatively considerable? (“Cumulatively considerable” means that the incremental effects of a project are considerable when viewed in connection with the effects of past projects, the effects of other current projects, and the effects of probable future projects)? c. Does the project have environmental effects, which will cause substantial adverse effects on human beings, either directly or indirectly?
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4.0 ENVIRONMENTAL ANALYSIS
This Initial Study/Mitigated Negative Declaration is based on the Environmental Impact Report and Environmental Assessment Mammoth/June Lakes Airport Land Use Plan (1986 EIR/EA)8, the Mammoth Lakes Airport Expansion, Subsequent Environmental Impact Report and Updated Environmental Assessment (1997 Subsequent EIR)9, and the Final Supplement to Subsequent Environmental Impact Report (2002 Supplement), which was certified by the Town in November 6, 2002,10 in that it: (a) relies on information and analysis presented in those documents, and (b) focuses its analysis on changes to the Project or the surrounding circumstances that may have occurred, since the Town certified the 2002 Supplement. Accordingly, this Initial Study/Mitigated Negative Declaration is prepared consistent with CEQA Guidelines 15162 through 15163, which govern follow-up environmental review.
4.1 AESTHETICS.
The findings of the 2002 Supplement (Page ES-4 and Pages III-5 to III-9) are summarized as follows:
A 25,000 square foot terminal would be constructed that is visible from a state designated scenic highway and National Forest lands used for public recreation. (The 2002 Supplement concluded this impact remained significant after mitigation.)
Virtually all of the Airport is within the scenic viewshed of U.S. Highway 395. Drivers and passengers passing by the Airport at approximately 65 miles per hour can see the Airport for approximately two minutes.
There would be periods of time when air carrier aircraft would be parked on the Airport ramp. Initial ramp development could support up to three air carrier aircraft with expansion capability of the ramp area of up to six aircraft. These aircraft would typically only be parked on the apron for the period of time it requires to unload disembarking passengers and load embarking passengers, fuel, and provisions. The air carrier aircraft at the Airport would be visible to drivers along U.S. Highway 395, but only for a short duration of time as are the existing general aviation aircraft. Because the runway itself would not be substantially visible to passersby on U.S. Highway 395, and the embankment would be completed with natural looking landscaping and aircraft on the new runway extension would be limited in number and in the duration of time sitting on the runway, the extension of the runway would result in less than significant impacts regarding scenic mountain vistas, scenic visual resources within a scenic highway, and degradation of the existing visual character of the Airport and its surrounding.
As these replacement and additional light sources would not create a new source of substantial light or glare, that would adversely affect day or nighttime views in the area
8 Mono County Airport Land Use Commission, Environmental Impact Report and Environmental Assessment Mammoth/June Lakes Airport Land Use Plan, July 1986. State Clearinghouse No. 86060901.
9 Town of Mammoth Lakes, Mammoth Lakes Airport Expansion, Subsequent Environmental Impact Report and Updated Environmental Assessment, 1997. State Clearinghouse No. 96112089.
10 Town of Mammoth Lakes, Final Supplement to Subsequent Environmental Impact Report, March 2002. State Clearinghouse No. 2000-034005.
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due to lamp shields and other design improvements, there would be no new significant environmental impacts in terms of light and glare.
The findings of the 2007 Draft EIS are summarized as follows:
The Proposed Action alternative would not result in light emissions or visual impacts because no physical changes would occur.11
Would the Project: a) Have a substantial adverse effect on a scenic vista?
Less Than Significant With Mitigation Incorporated. The Airport property generally slopes from the west to the east, with elevations ranging from approximately 7,135 feet at the westerly extent of the existing runway to approximately 7,065 feet at the easterly extent.12 The Airport property does not contain any prominent ridgelines, land, or water junctions, or other unique visual features. Sagebrush vegetation dominates in the nonpaved areas within the Airport property and its vicinity. 13 As specified in the GPEIR, a viewshed (or viewpoint) is an area that can be seen from a particular position (i.e., viewed from various locations in the Town and along roadways to and within the community). Virtually all of the Airport is within the scenic viewshed of U.S. Highway 395, which is located immediately south of the Airport. The California Department of Transportation (Caltrans) has designated U.S. Highway 395 as a scenic highway. Drivers and passengers passing the Airport, at approximately 65 miles per hour, can view the Airport for approximately two minutes.14 The primary views for westbound U.S. Highway 395 motorists approaching the Airport are westerly views of Mammoth Mountain, the Minarets, and Mounts Ritter and Banner, and southerly views of Mount Morrison and Laurel Mountain. The primary views for eastbound motorists approaching the Airport are southerly views of the Sierra Nevada, easterly/northeasterly views of the White Mountains, and northerly views of the Glass Mountains with rolling hills in the foreground. From the west, low rises intermittently block visibility of the Airport until approximately 0.5 mile west of the Hot Creek Fish Hatchery Road.
The 2002 Project involved various physical improvements to the Airport, including new fencing and a new 25,000-SF passenger terminal, among others. The 2002 Supplement concluded the new terminal would be visible from a state designated scenic highway and Inyo National Forest lands used for public recreation, thereby resulting in a significant unavoidable impact.15 No new facilities would be constructed as part of the proposed Project. Additionally, the proposed remodeling of the existing maintenance building is limited to new windows, doors, and cross- gabled entryways. No changes to the structure’s height (30 feet) or mass are proposed. Although the proposed passenger terminal (i.e., existing maintenance building) would be visible from U.S. Highway 395 and Inyo National Forest lands used for public recreation, the proposed terminal would not result in a substantial adverse effect on a scenic vista or scenic resources
11 U.S. Department of Transportation Federal Aviation Administration, Draft Environmental Impact Statement Request For Operations Specifications Amendment By Horizon Air to Provide Scheduled Air Service to Mammoth Yosemite Airport, November 2007, Page 5-2.
12 Ibid., Exhibit III-1, Elevation Profiles of Proposed Runway and U.S. Highway 395.
13 Ibid., Page 4-42.
14 Ibid., Page III-5.
15 Ibid., Page ES-4.
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within U.S. Highway 395, since it involves renovations to, but no physical expansion of, an existing building. The Project would be subject to compliance with the mitigation measure identified in the 2002 Supplement involving the building’s exterior design (i.e., colors and materials). Additionally, the proposed remodeling would be subject to compliance with the Town's Zoning standards and Design Guidelines, which regulate building height, massing, and placement. With implementation of the recommended mitigation and compliance with the Town's Zoning standards and Design Guidelines, the proposed modifications to the existing maintenance building would not result in a substantial adverse effect on a scenic vista or scenic resources within U.S. Highway 395.
The 2002 Project involved 23,650 annual aircraft operations. The 2002 Supplement concluded that the forecasted aircraft operations would result in less than significant impacts regarding scenic mountain vistas, scenic visual resources within a scenic highway, and degradation of the existing visual character of the Airport and its surroundings. The proposed Project involves 17,482 annual aircraft operations. Aircraft would be intermittently parked on the Airport ramp and thus visible (for a short time) from U.S. Highway 395 during aircraft fueling, and the loading and unloading of passengers and provisions. Comparatively, the current Project represents approximately 26 percent fewer aircraft operations than the project analyzed in the 2002 Supplement (23,650 annual aircraft operations). Project implementation would result in no greater impacts to scenic mountain vistas or scenic visual resources associated with annual aircraft operations than previously identified in the 2002 Supplement and conditions have not changed. Therefore, similar to the 2002 Project, the aircraft operations associated with the proposed Project would not result in a substantial adverse effect on a scenic vista or scenic resources within U.S. Highway 395.
Mitigation Measure:
AES-1 The use of earth tone colors and natural materials shall be emphasized in the terminal’s design in order to enhance compatibility with the natural setting, subject to Design Review approval by the Town’s Planning Commission. (2002 Supplement, Mitigation Type: 3). b) Substantially damage scenic resources, including, but not limited to, trees, rock outcroppings, and historic buildings within a state scenic highway?
Less Than Significant With Mitigation Incorporated. U.S. Highway 395, a designated scenic highway, is located immediately south of the Airport property. As concluded in Response 4.1.a above, the proposed Project would not substantially damage scenic resources within U.S. Highway 395. There are no trees, rock outcroppings, or historic buildings located on the Airport property or its immediate vicinity. No further environmental review is necessary.
Mitigation Measures: Refer to AES-1. c) Substantially degrade the existing visual character or quality of the site and its surroundings?
Less Than Significant With Mitigation Incorporated.
Short-Term Construction. The Project involves remodeling the interior and exterior of the existing maintenance building for use as a passenger terminal. During the construction phase, construction activities (i.e., construction debris and construction equipment) may be visible from
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U.S. Highway 395 and adjacent properties, although the level of activity would be minimal due to the limited scope of the proposed improvements. Therefore, construction-related activities would not substantially degrade the existing visual character or quality of the Airport site and its surroundings.
Long-Term Operations. The 2002 Project involved various physical improvements to the Airport, including new fencing and a new 25,000-SF passenger terminal, among others. The 2002 Supplement concluded the physical improvements would result in less than significant impacts to the existing visual character of the Airport and its surroundings. No new facilities would be constructed as part of the proposed Project. The proposed remodeling of the existing maintenance building would not increase the height or mass of the structure. Additionally, the proposed modifications to the existing gate would not alter its location or height. The proposed terminal would not degrade the existing visual character or quality of the Airport or its surroundings, since it involves an existing building. The Project would be subject to compliance with the mitigation measure identified in the 2002 Supplement involving the building’s exterior design. Additionally, the proposed remodeling would be subject to compliance with the Town's Zoning standards and Design Guidelines. The Project’s proposed modifications to the existing maintenance building would result in no greater impacts to the Airport’s visual character than previously identified in the 2002 Supplement. With implementation of the recommended mitigation and compliance with the Town's Zoning standards and Design Guidelines, the proposed modifications to the existing maintenance building would not substantially degrade the existing visual character or quality of the Airport and its surroundings.
The 2002 Project involved 23,650 annual aircraft operations. The 2002 Supplement concluded that the forecasted aircraft operations would not substantially degrade the existing visual character or quality of the Airport and its surroundings. The proposed Project involves 17,482 annual aircraft operations, which are similar in nature to the existing the Airport operations. The Project involves the continuation of an existing land use (i.e., an airport) and no physical changes to the existing facilities. The existing character and quality of the Airport would remain largely unchanged with the addition of scheduled commercial air service. Finally, the proposed Project would involve approximately 26 percent fewer aircraft operations than the project analyzed in the 2002 Supplement. The Project’s aircraft operations would result in no greater impacts to the Airport’s visual character than previously identified in the 2002 Supplement. Therefore, similar to the 2002 Project, the Project’s aircraft operations would not substantially degrade the existing visual character or quality of the Airport or its surroundings. No further environmental review is necessary.
Mitigation Measures: Refer to AES-1. d) Create a new source of substantial light or glare, which would adversely affect day or nighttime views in the area?
Less Than Significant Impact. There are two primary sources of light: light emanating from building interiors that pass through windows and light from exterior sources (i.e., automobile/aircraft headlights, street lighting, parking lot lighting, building illumination, security lighting, and landscape lighting). Depending upon the location of the light source and its proximity to adjacent light sensitive uses, light introduction can be a nuisance, affecting adjacent areas and diminishing the view of the clear night sky and, if uncontrolled, can disturb wildlife in natural habitat areas. Lighting associated with non-residential uses may cause spillover impacts to nearby sensitive receptors.
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The 2002 Project involved new lighting (25,000-SF passenger terminal) and modified existing lighting (i.e., runway edge, threshold, apron, building interior and exterior, and parking lot). The 2002 Supplement concluded that the new and modified existing lighting would not create a new source of substantial light or glare that would adversely affect day or nighttime views in the area and that there would be no new significant environmental impacts in terms of light and glare.
Currently, major sources of light and glare at the Airport are from light emanating from the terminal and other building interiors (including the existing maintenance building) and light from exterior sources (i.e., runway, apron, parking lot, signage, and security lighting). No new sources of light would be introduced with the proposed Project, as no new facilities would be constructed. Although conversion of the existing maintenance building to a passenger terminal would slightly increase the light emanating from the building’s interior due to increased levels of use, the increase would not result in an appreciable change in light or glare in the area. Project implementation would result in no greater impacts involving light and glare from buildings than previously identified in the 2002 Supplement. Therefore, light emanating from the proposed passenger terminal’s interior would not create a new source of substantial light or glare, which would adversely affect day or nighttime views in the area. Additionally, the proposed Project would be subject to compliance with the requirements of Code Chapter 17.34, Outdoor Lighting. Code Chapter 17.34 provides rules and regulations for outdoor lighting in order to prevent nuisances caused by unnecessary light intensity, direct glare and light trespass, and to protect the ability to view the night sky by restricting unnecessary upward projection of light. No further environmental review is necessary.
The proposed Project does not involve any new runway edge, threshold, apron, or parking lot lighting. Additionally, the Project involves scheduled commercial air service into the Airport; however, nighttime air carrier operations are not proposed. Therefore, the proposed Project would not create a new source of substantial light or glare in this regard. No further environmental review is necessary.
Mitigation Measures: No mitigation measures are required.
4.2 AGRICULTURE RESOURCES.
The findings of the 2007 Draft EIS are summarized as follows:
The Proposed Action alternative would not affect farmlands, because no physical changes would occur.
In determining whether impacts to agricultural resources are significant environmental effects, lead agencies may refer to the California Agricultural Land Evaluation and Site Assessment Model (1997) prepared by the California Department of Conservation as an optional model to use in assessing impacts on agriculture and farmland. Would the Project: a) Convert Prime Farmland, Unique Farmland, or Farmland of Statewide Importance (Farmland), as shown on the maps prepared pursuant to the Farmland Mapping and Monitoring Program of the California Resources Agency, to non-agricultural use?
No Impact. The Airport property is not designated as Prime Farmland, Unique Farmland or Farmland of Statewide Importance. The proposed Project does not involve any new
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construction. Project implementation would not result in the conversion of farmland to non- agricultural use.
Mitigation Measures: No mitigation measures are required. b) Conflict with existing zoning for agricultural use, or a Williamson Act contract?
No Impact. The Airport property is zoned Airport (A). Implementation of the Project would not conflict with existing zoning for agricultural use or a Williamson Act contract.
Mitigation Measures: No mitigation measures are required. c) Involve other changes in the existing environment, which due to their location or nature, could result in conversion of farmland to non-agricultural use?
No Impact. The Airport environs include open spaces used for agriculture. However, the Airport property is currently not in agricultural use. The Project does not involve any new airside or landside improvements. The Project involves remodeling an existing maintenance building. Project implementation would not result in environmental changes that would convert farmland to non-agricultural use.
Mitigation Measures: No mitigation measures are required.
4.3 AIR QUALITY.
The findings of the 2002 Supplement are summarized as follows:
Implementation of the proposed project would increase NOx and VOC emissions in the region due to additional aircraft activity at the Airport and the introduction of ground support equipment.
Introduction of air carrier service at the Airport would also increase the number of ground motor vehicle trips originating at the Airport and hence could cause additional particulate emissions. However, while introducing air carrier service to Mammoth Yosemite Airport would increase aircraft-related pollution in the future, as demonstrated in Table III-8 it could significantly reduce “highway” related emissions in the region as more people access the region by air in the long term.
As presented in Table III-8, it is expected that the change in operational emissions associated with the implementation of the proposed project would fall below established de minimis thresholds for ozone precursors and PM-10. The introduction of air carrier jet operations into Mammoth Yosemite Airport would increase aircraft NOx emissions and VOC emissions, however the project emissions are expected to be below de minimis thresholds.
Because the proposed project is not expected to result in a new significant impact on regional air quality, no new unavoidable adverse impacts would occur.
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Based on the analysis in this SSEIR and the information and conclusions in the prior environmental reviews, the project changes evaluated in this SSEIR would not result in any new significant cumulative impact on air quality or any substantially more severe cumulative impact on air quality.
The findings of the 2007 Draft EIS are summarized as follows:
When compared to the No-Action Alternative in both 2009 and 2015, air pollutant emissions for all EPA criteria pollutants associated with the Proposed Action would increase. These increases are attributable to the addition of scheduled air carrier operations and associated increase in motor vehicle trips.
Total direct and indirect emissions of PM10 associated with the Proposed Action are below the Clean Air Act (CAA) General Conformity Rule de minimis levels and these emissions are not regionally significant. Therefore, the requirements of Part 93, Subpart B do not apply and no formal General Conformity Determination is required.
The Transportation Conformity Rule requirements in the Clean Air Act do not apply to the Proposed Action as there are no planned off-airport roadway improvements associated with this Alternative.
Where available, the significance criteria established by the applicable air quality management or air pollution control district may be relied upon to make the following determinations. Would the Project: a) Conflict with or obstruct implementation of the applicable Air Quality Management Plan or Congestion Management Plan?
Less Than Significant Impact. The Great Basin Unified Air Pollution Control District (GBUAPCD) is responsible for enforcing applicable air quality regulations and ensuring the Federal and State standards are met. The Airport property is located in Mono County, within a valley on the eastern slopes of the Sierra Nevada Mountain Range. The area is included in the Great Basin Valley Air Basin (Basin), which includes Mono, Inyo, and Alpine counties. Each Basin in the State is designated either as “attainment,” “nonattainment,” or “unclassified,” depending on whether the Basin meets an ambient air quality standard. Effective January 23, 2005, the Mono County portion of the Basin has a nonattainment designation for Ozone (O3) 16 (State standard only). The entire Basin is designated in nonattainment of the federal PM10 (particulate matter below 10 microns in diameter) standard. The Mammoth Lakes area and Mono County are considered in attainment of all other Federal and State standards. Therefore, discussion of impacts for the Project will focus on those pollutants that are designated as nonattainment (O3 and PM10). Although Mono County is categorized as nonattainment of the State O3 standard, there is no ozone implementation plan for attaining the ozone standard in Mono County, nor is one required as outlined in the 2001 California Air Resources Board (CARB) Ozone transport review. Instead, the document states “Transport from the central portion of the (San Joaquin) Valley is responsible for ozone violations in Mammoth Lakes.”
The Air Quality Management Plan for the Town of Mammoth Lakes (AQMP) was released on January 19, 1990. The AQMP identified PM10 sources and mitigation that could be instituted to attain the National Ambient Air Quality Standards. The AQMP, prepared by GBUAPCD, is
16 Ozone forms when nitrous oxides (NOx) react with volatile organic compounds (VOC) on hot, sunny days.
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required under the Federal Clean Air Act (CAA) and will become part of the State Implementation Plan to attain Federal standards. The AQMP identifies exceedances of the PM10 standard that occur predominantly in the winter due to increased emissions from wood stoves, fire places, and traffic related road dust and cinders. This change is also fueled largely by the influx of visitors to the Mammoth Lakes area during ski season. The combination of periods of meteorological stagnation and peak periods at the ski resort results in violations of PM10 standards. The AQMP includes a control strategy to satisfy the Federal CAA requirement by demonstrating how the Mammoth Lakes area will meet and maintain the National Ambient Air Quality standards for PM10. The road dust reduction measure in the AQMP limits peak day traffic loads to 106,600 vehicle miles traveled (VMTs). This reduction measure has been incorporated into Code Chapter 8.30, Particulate Matter Ordinance. The Particulate Matter Ordinance largely implements the mitigation measures identified in the AQMP.
Project implementation would result in increases in air pollutant emissions for all U.S. Environmental Protection Agency’s (EPA) criteria pollutants. These increases would be attributable to the addition of scheduled air carrier operations and associated increase in motor vehicle trips. The proposed addition of scheduled air carrier operations and associated increase in motor vehicle trips were considered within the 2002 Supplement. Implementation of the proposed Project would be consistent with the analysis presented in the 2002 Supplement, and would result in no greater impacts associated with AQMP conformity than previously identified. Therefore, Project implementation would not conflict with or obstruct implementation of any local or regional air quality plans, since the indicated emissions are within the parameters identified in the 2002 Supplement. Compliance with the policies and programs of the GPEIR and mitigation measures set forth in the 2002 Supplement are expected to reduce potential impacts associated with air quality plans to below levels of significance.
Mitigation Measures: No mitigation measures are required. b) Violate any air quality standard or contribute substantially to an existing or projected air quality violation?
Less Than Significant Impact.
Short-Term Impacts
The current Project also involves remodeling the existing maintenance building at the Airport for use as a 5,000-SF passenger terminal. The passenger terminal would contain TSA facilities, and may include baggage handling, customer services, rental cars, and food services within the renovated structure. No new facilities would be constructed as part of the proposed Project. Therefore, Project implementation would result in no greater impacts associated with short-term air emissions than previously identified in the 2002 Supplement. No further environmental review is necessary.
Long-Term Impacts
Emissions Calculation Methodology
The sources of air pollutant emissions include aircraft, ground support equipment, motor vehicles using the Airport access roads and parking facility, deicing activities, and fuel storage facilities. This evaluation does not include a fugitive dust of equipment emissions analysis due to construction activities, since no new facilities would be constructed as part of the proposed
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Project. Any minor modifications to the proposed terminal facility would be primarily constructed with manual labor and electrical equipment (i.e., skill saws, pneumatic hammers, etc.).
For this analysis, standard Emissions Dispersion & Modeling System (EDMS) parameters and databases were used except where MMH-specific inputs were available and more appropriate. EDMS is identified as the “required” model by FAA and includes EPA’s AERMOD model for performing dispersion modeling. AERMOD is an approved model by the EPA for conducting airport air quality assessments. Each of the sources of emissions included in the emissions inventory is briefly described below.
Aircraft Data. FAA approved forecasts of future year operations at MMH by aircraft type (e.g., commercial and General Aviation [GA]) were used as the basis for the air quality analysis. Aircraft/engine combinations and individual aircraft engine emission factors were obtained from the EDMS database. Annual aircraft Landing and Take Off operations data (LTOs) and fleet mixes were developed specifically for this analysis and are presented in Appendix 9.1, Air Quality Data. One LTO cycle equals two operations (i.e., one landing and one takeoff) and, within EDMS, these activities are further subdivided into the following four modes:
Approach/Landing Mode - Begins when an aircraft descends below the atmospheric mixing height (a default value of 3,000 feet above ground level [AGL] was used in this analysis) and ends when the aircraft touches down on the runway and decelerates to the taxi/idle mode. Depending on the aircraft type, this time varies from 3.57 to 9.06 minutes.
Climbout Mode - Begins when the aircraft is 1,000 feet AGL and ends when the aircraft reaches an altitude of 3,000 feet AGL (the default atmospheric mixing height). Again, depending on the aircraft type, this time ranges from 0.59 to 4.53 minutes.
Takeoff Mode - Begins when takeoff power is applied to an aircraft and ends when an aircraft reaches 1,000 feet AGL. This time varies between 0.69 and 2.27 minutes, again by aircraft type.
Taxi/Idle Mode - Comprises all of the time periods when an aircraft is on the airport taxiway system or terminal area aprons with its engines running. This includes all ground-based delays incurred or encountered between the runway ends and the terminal gates. The total duration of this mode is largely a function of the airport design, layout, and operational capacity and assumes that all aircraft travel at approximately the same speed while on the airfield. For this air quality analysis, the full time for this mode (which includes taxi-in, taxi-out, and delay) was calculated to be 5.8 minutes under existing and future conditions, based on actual travel distance at a speed of 15 miles per hour (mph).
EDMS automatically calculates the times-in-mode for the approach/landing, climb-out, and takeoff modes for each aircraft classification type (e.g., jet, turbo prop, etc.). A mixing height of 3,000 feet AGL was used in the analysis. Consistent with FAA guidelines17, it was also assumed that aircraft emissions above the atmospheric mixing height would have no ground-level effect; therefore, these emissions are not included in the inventory.
17 U.S. Department of Transportation Federal Aviation Administration Office and Environment and Energy, Consideration of Air Quality Impacts by Airplane Operations at or above 3,000 feet AGL, September 2000.
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Motor Vehicle Data. On-site motor vehicles (i.e., cars, vans, limousines, trucks, etc.) are those that are operating on the airport’s primary internal roadway network and within the parking facilities located on the airport. These motor vehicles are primarily associated with airport patron and employee trips operating within the airport boundary. Traffic volumes on these roadways and facilities were developed specifically for this analysis. The motor vehicle engine emission factors were derived from the CARB mobile source emissions model, EMFAC2002. For this analysis, Mono County-specific motor vehicle operating characteristics (i.e., fleet mix, operating temperatures, etc.) were used in EMFAC2002. These and other supporting data used to assess on-site motor vehicle emissions are presented in Appendix 9.1. It should be noted that the motor vehicle emissions were generated with year 2009 and 2015 traffic data with the EMFAC 2002 model. Although the Traffic Impact Analysis prepared by LSA Associates (February 2008) presents 2025 traffic volumes, Year 2015 motor vehicle emissions were utilized from the 2007 Draft EIS as they are more conservative in nature.
Ground Support Equipment. Ground Support Equipment (GSE) associated with both commercial and GA aircraft at MMH can include baggage and pushback tugs; belt loaders; fuel trucks and other service vehicles; and auxiliary power units (APU). MMH-specific GSE fleet, default fuel types and operating times, and the default GSE emission factors which are contained in the EDMS GSE database were used.
Deicing Fluid Usage Data. Annual deicing fluid usage and fuel consumption data were developed specifically for this analysis and are presented in Appendix 9.1. Data provided by the Town indicated that no deicing was performed at MMH in 2005. Data for the 2009 and 2015 scenarios were supplied by Horizon Air (approximately 3,700 gallons per year in 2009, and approximately 16,800 gallons per year in 2015).
Fuel Consumption Data. VOC emissions of Jet A fuel and aviation gasoline (Avgas) represent potential sources of evaporative VOC emissions. For this analysis, the amounts of fuel-related VOC emissions generated were based on the types and amounts of fuels stored and dispensed at MMH. Future year emissions were adjusted from existing values according to the forecasted increase in GA aircraft operations at MMH for the years 2009 and 2015. Due to operational considerations of Horizon Airlines and the short flight time, it was assumed that the scheduled commercial aircraft would refuel at the base airport and would not refuel at Mammoth Yosemite Airport.
Existing Conditions
EDMS was used to estimate emissions for CO, VOCs, and NOx as precursor pollutants to O3 formation, PM10, PM2.5, and SO2. The operational air pollutant emissions inventory for MMH for the 2005 existing conditions is summarized in Table AQ-1, Air Pollutant Emissions for the 2005 Existing Condition.
Operational Emissions
As documented in the 2002 Supplement, the 2002 Project involved 37,000 enplanements at Year 2007 and 333,800 enplanements in Year 2022. Table AQ-2, Air Pollutant Emissions for the 2002 Project, outlines the forecast emissions associated with those anticipated operations.
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Table AQ-1 Air Pollutant Emissions for the 2005 Existing Condition
Source CO VOC NOx PM10/PM2.5 SO2 Aircraft1 57.01 1.45 1.38 0.582 0.20 Ground Support Equipment 0.07 0.02 0.29 0.01 0.06 Motor Vehicles 2.16 0.10 0.38 0.01 0.00 Fuel Storage and Deicing NA 2.80 NA NA NA Annual Total (tons/year) 59.24 4.25 2.05 0.60 0.26 Notes: 1 – Emissions based on 12,800 annual aircraft operations and an estimated taxi time of 5.8 minutes in 2005. 2 – Results include particulate matter emissions from piston aircraft engines not available in EDMS, using FAA’s First order approximation methodology. 3 – “NA” means the source does not emit this type of pollutant. Source: U.S. Department of Transportation Federal Aviation Administration, Draft Environmental Impact Statement Request For Operations Specifications Amendment By Horizon Air to Provide Scheduled Air Service to Mammoth Yosemite Airport, November 2007.
Table AQ-2 Air Pollutant Emissions for the 2002 Project
Source CO VOC NOx PM10/PM2.5 SO2 YEAR 20071 Aircraft 121.66 6.69 20.29 0.84 0.24 Ground Support Equipment 78.36 1.81 6.59 0.17 0.22 Motor Vehicles 12.55 1.75 1.48 0.08 25.47 Fuel Storage and Deicing NA 0.31 NA NA NA Annual Total (tons/year) 212.57 10.57 28.37 1.09 25.93 YEAR 20222 Aircraft 200.00 11.27 41.44 1.67 0.44 Ground Support Equipment 138.44 3.21 11.55 0.30 0.38 Motor Vehicles 20.68 2.72 2.86 0.16 51.21 Fuel Storage and Deicing NA 0.31 NA NA NA Annual Total (tons/year) 359.12 17.52 55.85 2.13 52.03 Notes: 1 – Emissions based on 159,900 enplanements and 14,105 annual aircraft operations. 2 – Emissions based on 333,800 enplanements and 23,650 annual aircraft operations. 3 – “NA” means the source does not emit this type of pollutant. Source: Town of Mammoth Lakes, Final Supplement to Subsequent Environmental Impact Report, March 2002.
As shown in Table AQ-3, Air Pollutant Emissions for the 2009 and 2015 Conditions, total criteria air pollutant emissions associated with the 2009 condition are estimated to be 67.69 tons per year (tpy) of CO, 4.63 tpy of VOC, 2.60 tpy of NOx, 0.67 tpy of PM10/PM2.5, and 0.30 tpy of SO2. Total pollutant emissions associated with the 2015 condition are estimated to be 92.41 tpy of CO, 5.41 tpy of VOC, 4.34 tpy of NOx, 0.93 tpy of PM10/PM2.5, and 0.49 tpy of SO2 as shown in Table AQ-3.
The 2002 Supplement concluded that the emissions associated with the forecasted aircraft operations would fall below established de minimus levels. No new standards have been established since 2002. The 2002 Project involved 333,000 annual enplanements and 23,650 annual aircraft operations, as well as various physical improvements to the Airport, including runway extension and widening, a new 25,000-SF passenger terminal, among others. The
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current Project considers 67,168 annual enplanements, 17,482 annual aircraft operations, and involves remodeling the existing maintenance building for use as a passenger terminal. No new facilities would be constructed. Comparatively, the current Project represents approximately 80 percent fewer enplanements and approximately 26 percent fewer aircraft operations, than the project analyzed in the 2002 Supplement. It is further noted that the emissions predicted for the 2002 Project and the current Project both fall below the de minimus standards.18 No further environmental review is necessary.
Table AQ-3 Air Pollutant Emissions for the 2009 and 2015 Conditions
Source CO VOC NOx PM10/PM2.5 SO2 YEAR 20091 Aircraft1 60.45 1.54 1.78 0.63 0.24 Ground Support Equipment 4.60 0.18 0.34 0.02 0.06 Motor Vehicles 2.64 0.11 0.48 0.02 <0.01 Fuel Storage and Deicing NA 2.80 NA NA NA Annual Total (tons/year) 67.69 4.63 2.60 0.67 0.30 YEAR 20152 Aircraft1 69.44 1.76 3.15 0.81 0.38 Ground Support Equipment 20.67 0.76 0.69 0.09 0.11 Motor Vehicles 2.30 0.09 0.50 0.03 <0.01 Fuel Storage and Deicing NA 2.80 NA NA NA Annual Total (tons/year) 92.41 5.41 4.34 0.93 0.49 Notes: 1 – Emissions based on 14,249 annual aircraft operations. 2 – Emissions based on 17,483 annual aircraft operations. 3 – “NA” means the source does not emit this type of pollutant. Source: U.S. Department of Transportation Federal Aviation Administration, Draft Environmental Impact Statement Request For Operations Specifications Amendment By Horizon Air to Provide Scheduled Air Service to Mammoth Yosemite Airport, November 2007.
Global Climate Change
In addition to the criteria pollutants for which direct regulatory standards have been established, the construction and operation of the project will involve the production of a variety of other gases, such as carbon dioxide, which are believed to play a role in on-going climate change. This section summarizes the state of scientific inquiry into climate change, and the possible effects of this project on that phenomenon.
Climate change refers to any significant change in measures of climate (such as temperature, precipitation, or wind) lasting for an extended period (decades or longer). Climate change may result from natural factors, natural processes within the climate system, and/or human activities (anthropogenic activities). Atmospheric greenhouse gases (GHGs) and clouds within the Earth’s atmosphere influence the Earth’s temperature by absorbing most of the infrared radiation rising from the Earth’s sun-warmed surface that would otherwise escape into space.
18 As a means of determining whether or not the requirements of the General Conformity Rule apply, the U.S. EPA has established de minimis levels for all nonattainment air pollutants. The applicable de minimis values for this nonattainment area is 100 tpy for PM10. Because the area around MMH is designated as in attainment with respect to ozone, CO, NO2, PM2.5, and SO2, no de minimis values apply to these criteria pollutants.
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This process through which heat is retained in the troposphere is commonly known as the greenhouse effect.19
20 GHGs include, but are not limited to, the following gases : water vapor (H20), carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and sulfur hexafluoride (SF6). In addition to these six major GHGs (excluding water vapor), other compounds have the potential to contribute to the greenhouse effect. Some of these substances are identified as stratospheric ozone depletors; therefore, their gradual phase out is currently in effect. Hydrochlorofluorocarbons (HCFCs), 1,1,1 trichloroethane or methyl chloroform, chlorofluorocarbons (CFCs), and ozone form these compounds.
State of Scientific Inquiry
Although the occurrence of Global Climate Change (GCC) now is a widely accepted theory, the precise extent of GCC and the exact contribution from anthropogenic sources is still a matter of serious discussion within the scientific community. Climate change is a global environmental issue, not just a local environmental issue. GHGs cannot be attributed to a direct health effect like criteria pollutants monitored by the CARB (i.e., carbon monoxide, particulate matter, ozone, nitrogen oxides, and sulfur dioxide).
Anthropogenic increases in GHGs have been shown to be highly correlated with increases in the surface temperatures on earth. However, the correlation has not been linked definitively to causation. Because the interval of rising temperatures coincides with the time of rapidly increasing GHG emissions, some have concluded that the two phenomena are causally related. Since historical temperature data before 1950 is based on relatively few data that are unequally distributed across the globe, it is difficult to make a convincing case.
The mechanisms involved in land-atmosphere interactions are not understood or represented in climate models.21 Causes of earlier historical temperature changes are unknown but could be due to changes in solar radiation, the Earth's orbit, the composition of the atmosphere, ocean circulation patterns, and other factors.22 Although average temperatures in the Northern Hemisphere appear to have been relatively stable from about 1000 to the mid-1800s based on temperature proxy records from tree rings, corals, ice cores and historical observations,23 there is a significant amount of uncertainty related to proxy temperature records, especially those extending far back into the past.24
19 The troposphere is the bottom layer of the atmosphere, which varies in height from the Earth’s surface to 10 to 12 kilometers.
20 All Global Warming Potential (GWP) are given as 100 year GWP. Unless noted otherwise, all GWP were obtained from the Intergovernmental Panel on Climate Change (Intergovernmental Panel on Climate Change, Climate Change, The Science of Climate Change – Contribution of Working Group I to the Second Assessment Report of the IPCC, 1996).
21 National Research Council, Radiative Forcing of Climate Change: Expanding the Concept and Addressing Uncertainties, 2005.
22 California Department of Water Resources, Progress on Incorporating Climate Change into Management of California’s Water Resources, July 2006.
23 Intergovernmental Panel on Climate Change, Climate Change 2001: Synthesis Report. A Contribution of Working Groups I, II, and III to the Third Assessment Report of the Intergovernmental Panel on Climate Change, 2001.
24 California Department of Water Resources, Progress on Incorporating Climate Change into Management of California’s Water Resources, July 2006.
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Climate change prediction is difficult as it involves complex, nonlinear interactions among all components of the earth’s environmental system.25 Human activities have an influence on the climate system and these activities are not limited to GHG emissions.26 Other factors that influence the climate system include changing land uses and natural causes, which further complicates the issue of climate prediction.27 Some climate changes are larger and occur faster than those previously predicted by climate models, while other indicators show some stabilizing.28 Although currents are relatively warm around the edges of the Arctic Ocean, the North Pole ocean temperatures are returning to 1990 values.29
Potential Environmental Effects of Climate Change
The primary example of GCC has been a rise in average global tropospheric temperature of 0.2° Celsius per decade, determined from meteorological measurements world wide between 1990 and 2005.30 Climate change modeling using 2000 emission rates shows that further warming may occur, which would induce further changes in the global climate system during the current century.31 Changes to the global climate system, ecosystems, and to California could include, but would not be limited to: the loss of sea ice and mountain snow pack (i.e., Sierra Mountains); the rise in the global average sea level; changes in weather (i.e., precipitation, ocean salinity, and wind patterns), and more extreme weather (i.e., droughts, heavy precipitation, heat waves, extreme cold, and increased intensity of tropical cyclones); and an increased potential for the erosion of California’s coastlines and seawater intrusion into the Delta and levee systems.32
Strategies to Respond to Global Climate Change
To meet the greenhouse gas emission reduction targets outlined in Executive Order S-3-05, the Governor directed the Secretary of the California Environmental Protection Agency (CalEPA) to coordinate with the Secretary of the Business, Transportation and Housing Agency, Secretary of the Department of Food and Agriculture, Secretary of the Resources Agency, Chairperson of the Air Resources Board, Chairperson of the Energy Commission and President of the Public Utilities Commission. The Secretary of CalEPA and representatives from the agencies listed above are collectively referred to as the California Climate Action Team (CCAT). Table AQ-4, Applicable Global Climate Change Strategies, provides a list of recommended measures and strategies to help reduce global climate impacts that was provided by the CCAT. The strategies listed in Table AQ-4 would directly apply to the proposed Project. Table AQ-4 provides an analysis of the Project’s consistency with the CCAT’s recommended GHG reduction strategies.
25 American Association of State Climatologists, Policy Statement on Climate Variability and Change, February 2, 2002. http://www.stateclimate.org/publications/files/aascclimatepolicy.pdf
26 Ibid.
27 Ibid.
28 American Meteorological Society Atmospheric News, NOAA Arctic ‘Report Card’ Shows Continued Climate Changes, October 17, 2007. http://www.ametsoc.org/amsnews/news.html#noaa
29 Ibid.
30 Intergovernmental Panel on Climate Change, Climate Change 2007: The Physical Science Basis, Summary for Policymakers, February 2007.
31 Ibid.
32 Ibid.
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Table AQ-4 Applicable Global Climate Change Strategies
Strategies for Reducing Greenhouse Gas Emissions1 Project Consistency Vehicle Climate Change Standards. AB 1493 (Pavley) required the Following construction, the majority of the vehicles that access state to develop and adopt regulations that achieve the maximum the Project would be expected to be in compliance with any feasible and cost-effective reduction of climate change emissions vehicle standards that CARB adopts. emitted by passenger vehicles and light duty trucks. Regulations were adopted by the CARB on September 2004. Other Light Duty Vehicle Technology. New standards would be Following construction, the majority of the vehicles that access adopted to phase in beginning in the year 2017 model year. the Project would be expected to be in compliance with any vehicle standards that CARB adopts. Diesel Anti-Idling. In July 2004, the CARB adopted a measure to limit All vehicles, including diesel trucks accessing the Project site, diesel-fueled commercial motor vehicle idling. would be subject to the CARB measures and would be required to adhere to the 5-minute limit for vehicle idling. Hydrofluorocarbon Reduction. 1) Ban retail sale of HFC in small cans; This measure applies to consumer products. When CARB 2) Require that only low GWP refrigerants be used in new vehicular adopts regulations for these reduction measures, any products systems; 3) Adopt specifications for new commercial refrigeration; 4) that the regulations cover would comply with the measures. Add refrigerant leak-tightness to the pass criteria for vehicular inspection and maintenance programs; 5) Enforce federal ban on releasing HFCs. Alternative Fuels: Use of alternative fuels such as biodiesel blends and These standards would require vehicles to use alternative fuels. ethanol, and use of non-petroleum fuels. Future vehicle purchases will be based on the benefits of using alternative fuels. Building Energy Efficiency Standards: New standards would be The proposed Project would be required to comply with the new adopted to update the CECs building energy efficiency standards. standards. Heavy-Duty Vehicle Emission Reduction Measures. Increased These are CARB enforced standards; vehicles that access the efficiency in the design of heavy-duty vehicles and an education Project that are required to comply with the standards would program for the heavy-duty vehicle sector. comply with the strategy. Achieve 50% Statewide Recycling Goal and Zero Waste – High The proposed Project would be required to comply with the Recycling - 1) Design locations for separate waste and recycling strategy, and install separate waste and recycling receptacles receptacles; and 2) Utilize recycled components in the building design. and utilize recycled components in building design. Appliance Energy Efficiency Use. Use of energy efficient appliances In October 2006, the State of California adopted Appliance (i.e., refrigerators, stoves, etc.). Efficiency Regulations, which include standards for both Federally regulated appliances and non-Federally-regulated appliances. Water Use Efficiency Features. To increase water use efficiency, The proposed Project would be required to comply with include use of both potable and non-potable water to the maximum California Health and Safety Code (HSC) section 17921.3, extent practicable and use of low flow appliances (i.e., toilets, faucets, which sets efficiency standards for bathroom fixtures. etc). Additionally, California Code of Regulations, Title 20, Division 2, Chapter 4, Article 4, Section 1605.3 sets standards for washing machines and commercial pre-rinse spray valves. Notes: 1 – Only the applicable strategies for reducing GHG emissions were included. Source: California Environmental Protection Agency, Climate Action Team Report to Governor Schwarzenegger and the Legislature, March 2006.
Regulatory Setting
International regulatory programs addressing GCC include the Kyoto Protocol and Western Regional Climate Action Initiative. The Kyoto Protocol sets an emissions reduction target for six GHGs by the period of 2008 to 2012 for participating countries. The Western Regional Climate Action Initiative requires participating U.S. States and countries to identify, evaluate, and
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implement ways to reduce GHG emissions as well as design a regional market-based multi- sector mechanism. The Town joined the U.S. Mayors Climate Protection Agreement by action of the Town Council in February 2007.
State of California regulatory programs include Assembly Bill (AB) 1493, AB 32, Senate Bill (SB) 1368, SB 107, SB 1505, SB 97, Executive Order (EO) S-3-05, EO S-1-07, EO S-20-04, and the California Solar Initiative. AB 1493 set the GHG emission standard for passenger vehicles. AB 32 is the California Global Warming Solutions Act which establishes a statewide program to limit GHG emissions from all major industries with penalties for noncompliance. SB 1368 requires the California Public Utilities Commission (CPUC) to establish a GHG emission performance standard for baseload generation from investor owned utilities. SB 107 requires investor owned utilities in California to increase their total procurement of eligible renewable energy resources. SB 1505 establishes environmental performance standards for the production and use of hydrogen fuel for transportation purposes in California. SB 97 requires the California Office of Planning and Research (OPR) to develop CEQA Guidelines for analysis and, if necessary, the mitigation of GHG emissions or the effects of GHG to the Resources Agency. EO S-3-05 establishes GHG emissions reduction targets. EO S-1-07 establishes new Low Carbon Fuel Standard for transportation fuels sold within California. EO S-20-04 establishes California’s priority for energy and resource-efficient high performance buildings. The California Solar Initiative has a goal to create 3,000 megawatts of new solar-produced electricity by 2017. Although adopted, many of these laws are in the process of developing implementation programs and do not currently have accepted routine application practices.
Court Cases
Court cases have shaped and molded the regulatory environment in the past and will continue to frame regulations the future. In the Massachusetts v. U.S. Environmental Protection Agency case, the United States Supreme Court ruled that the EPA is required to regulate CO2 as a GHG under the federal Clean Air Act. In the People of the State of California, ex rel. Attorney General Edmund G. Brown Jr. v. County of San Bernardino, San Bernardino County Board of Supervisors, California’s Attorney General Brown and the County of San Bernardino came to an agreement regarding the County’s General Plan which includes the County implementing a Greenhouse Gas Emissions Reduction Plan.
Both Center of Biological Diversity v. City of Banning and Center for Biological Diversity, et. al. v. the City of Desert Hot Springs, et. al are cases where agencies approving projects were sued because the environmental documentation did not consider the effects of increased GHG emissions.
In State of California v. U.S. EPA, the court declined California’s request to compel the EPA to allow California to impose GHG standards on vehicles.
Project Related Greenhouse Gas Emissions and Measures to Reduce Greenhouse Gas Emissions
Of the various GHG, CO2 is the only one likely to be related to the project in any material quantities. The CO2 emissions for the Project’s proposed ground operations are based upon EMFAC2007 computer model outputs and information contained within the 2007 Draft EIS. Aircraft CO2 emissions were not quantified, as the Airports Council International (ACI) and the International Civil Aviation Organization (ICAO) advise airports to account for their own ground based emissions, and airlines to assess aircraft related GHG’s, so as to avoid any potential
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double counting. CO2 emissions were not quantified for deicing, as the process does not produce CO2 emissions. CO2 emissions associated with vehicle trips were quantified for two projected years, 2009 and 2015. In 2009, 18,906.98 tons per year of CO2 would be emitted, while 72,586.57 tons per year of CO2 would be emitted during Year 2015. The determination of CO2 emissions from ground Support Equipment would be speculative, as the EDMS model used to assess pollutants from this source does not calculate CO2 emissions. Additionally, the information required to produce quantified rates using emission factors or other models requires more detail than is available at this time (i.e., facility energy requirement rates, model types of ground equipment, etc.). Typically, ground operation activities are finalized during final negotiations with the aircraft carrier.
The Town is implementing many strategies to address GCC. These include Community Goals and Policies, Town-Wide Strategies, and Specific Project Strategies to Achieve Carbon Neutral Outcomes. Applicable Community Goals and Policies are listed in the Town’s General Plan in the Resource Management and Conservation Chapter. Townwide Strategies include the Town’s aggressive regulations pertaining to air pollution and the reduction of particulate matter emissions, provisions that regulate the intensity of outdoor lighting, and aggressive increases in solid waste diversion/reduction. Specific Project Strategies to Achieve Carbon Neutral Outcomes for the proposed Project include the following:
Reuse and rehabilitation of an existing building; Public transportation and/or hotel courtesy shuttles for passengers; Recycling runway pavement and excavation material; Using low energy lighting/retrofits internally and externally; Use of electric heating/air conditioning instead of propane; Availability of electrical power for the aircraft at the gate; Restricting processing commercial flights through the terminal to one at a time; Deicing fluid contained on-site is disposed of at existing hazardous materials collection site; No washing facilities on site; No overnight layovers at the Airport; No jet fuel service/hydrant fueling on site; and Airport provided recycling bins at the Airport.
Reduction Measures
Table AQ-5, Potential Greenhouse Gas Reduction Measures, lists potential specific Airport reduction measures that could be implemented at Project implementation or implemented later at a more appropriate time.
Findings
Currently, there are no CEQA Thresholds of Significance established for GHGs; however, the Governor’s Office of Planning and Research is in the process of developing CEQA guidelines “for the mitigation of greenhouse gas emissions or the effects of greenhouse gas emissions.”
In the absence of available specific information, CEQA requires an agency to engage in forecasting “to the extent that an activity could reasonably be expected under the circumstances. An agency cannot be expected to predict the future course of governmental regulation or exactly what information scientific advances may ultimately reveal.” The CEQA Guidelines specifically authorizes lead agencies to conclude discussion of an impact if the lead agency finds that further discussion would be speculative (CEQA Guideline 15145). Further,
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the California Supreme Court has specifically upheld this type of finding in an EIR when there is no accepted methodology or standard to evaluate a potential cumulative impact (Laurel Heights Improvements Association v. Regents (1993) 6 Cal.App.4th 1112, 1137). In Laurel Heights, the draft EIR stated that “there are no accepted methodologies or standards by which the quantitatively measured cumulative toxic emission impacts of all potential sources of toxic air emissions in Laurel Heights vicinity.” Based upon this, the EIR concluded “the potential cumulative impacts of toxic air emissions are too speculative for evaluation.” Based on CEQA Guideline 15145, the California Supreme Court upheld that conclusion in the EIR. Similarly, an Appellate Court held that an air district was not required to evaluate as yet unknown technologies in its environmental assessment of a new air quality rule (Alliance of Small Emitters/Metals Industry v. South Coast Air Quality Management Dist. (1997) 60 Cal.App.4th 55, 57–60).
Table AQ-5 Potential Greenhouse Gas Reduction Measures
Specific Measure Terminal Project A firm commitment to build and operate all new gates to provide The Mammoth Yosemite Airport would have landside power landside power to aircraft at the gate. available to the aircraft. A firm commitment and timetable to retrofit all existing gates to The Mammoth Yosemite Airport would have landside power provide landside power to aircraft at the gate. available to the aircraft. A requirement by the Mammoth Yosemite Airport that aircraft Horizon Airlines has already agreed to using landside use landside power while at the gate. power and the Mammoth Yosemite Airport would work toward including language in the operating agreement Provision by the Mammoth Yosemite Airport of landside power The Mammoth Yosemite Airport would not have cargo at cargo gates and in hangars, and a requirement by the Airport gates or commercial aircraft hangars. that cargo companies use that landside power. Use of cool roofs (or rooftop solar panels) on all new buildings, No new facilities would be constructed as part of the and cool pavements for new-paved or rebuilt areas at curbside proposed Project. Rather, an existing maintenance facility or that carry traffic. would be remodeled into a terminal. The Town’s policy is to build new buildings using green technology to the greatest extent possible. LEED Gold certification (or equivalent) of new construction. The Town’s policy is to establish incentives for green building practices and LEED certified buildings. A firm commitment to use electric or alternative fuel tow vehicles There would be no towing at the Airport due to the small to push aircraft to and from runways and aprons, during all size of the runway and taxiway. However, all jet porters are except most congested peek periods. electric and all on-airport general circulation is performed by electric golf carts. A firm commitment to sell unleaded mogas at the general The Mammoth Yosemite Airport already sells unleaded aviation facility for those planes that can run on it. mogas. A requirement by the Mammoth Yosemite Airport that firms The Town’s current requirement is to ensure that all performing construction use equipment that either runs on vehicles meet the requirements of state law and that they alternative fuels or employs CARB-certified particulate traps. limit idling time during warm up and operations. A requirement by the Mammoth Yosemite Airport that all shuttle Current vehicles do not run on alternative fuels. services with two or more permits serving the Airport (e.g., hotel, Consideration would be given to future vehicle purchases door-to-door) commit to have at least half their shuttles powered by alternative fuels. Implementation by the Mammoth Yosemite Airport of an The Town already implements an aggressive recycling aggressive recycling program for Airport, all tenants, businesses program and the Airport, which would continue with Project and concessions operating at the Airport, and all airlines. implementation. A commitment by the Mammoth Yosemite Airport to work with all There are no tenants or concession facilities at the Airport. tenants, businesses, and concessions operating at the Airport to reduce their carbon footprints.
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In the absence of available specific information, CEQA requires an agency to engage in forecasting “to the extent that an activity could reasonably be expected under the circumstances. An agency cannot be expected to predict the future course of governmental regulation or exactly what information scientific advances may ultimately reveal.” The CEQA Guidelines specifically authorizes lead agencies to conclude discussion of an impact if the lead agency finds that further discussion would be speculative (CEQA Guideline 15145). Further, the California Supreme Court has specifically upheld this type of finding in an EIR when there is no accepted methodology or standard to evaluate a potential cumulative impact (Laurel Heights Improvements Association v. Regents (1993) 6 Cal.App.4th 1112, 1137). In Laurel Heights, the draft EIR stated that “there are no accepted methodologies or standards by which the quantitatively measured cumulative toxic emission impacts of all potential sources of toxic air emissions in Laurel Heights vicinity.” Based upon this, the EIR concluded “the potential cumulative impacts of toxic air emissions are too speculative for evaluation.” Based on CEQA Guideline 15145, the California Supreme Court upheld that conclusion in the EIR. Similarly, an Appellate Court held that an air district was not required to evaluate as yet unknown technologies in its environmental assessment of a new air quality rule (Alliance of Small Emitters/Metals Industry v. South Coast Air Quality Management Dist. (1997) 60 Cal.App.4th 55, 57–60).
GCC impacts are influenced by cumulative emissions from human activities in the region, the state, and the world. There is significant uncertainty involved in making predictions regarding the extent to which the operations of the proposed Project would affect GHG emissions and global climate change. Section 15145 of the CEQA Guidelines provides that, if after a thorough investigation a lead agency finds that a particular impact is too speculative for evaluation, the agency should note its conclusion and terminate discussion of the impacts.
This document goes beyond that limited review, and includes substantial discussion of the issue of GCC, an analysis of the GHG emissions and GCC aspects of the proposed project, as well as consideration of measures that may be utilized in airport projects to respond to GCC concerns, and identifies the measures that are relevant to this project, and can and will be implemented to address GCC concerns.
Based on this evidence, it does not appear that the proposed project would contribute significantly to GCC or would be inconsistent with any State or Town programs that address GCC impacts. Moreover, the project incorporates measures directed at reducing GCC impacts.
Mitigation Measures: No mitigation measures are required. c) Result in a cumulatively considerable net increase of any criteria pollutant for which the air basin is nonattainment under an applicable Federal or State ambient air quality standard (including releasing emissions, which exceed quantitative thresholds for ozone precursors)?
Less Than Significant Impact. The GBUAPCD does not have numerical thresholds for criteria pollutants to determine whether the Project would result in a cumulatively considerable net increase of PM10 or O3 precursors, other than those established in State and federal standards; however, as previously discussed, the project would fall below the de minimus thresholds. Project implementation would result in no greater impacts associated with air emissions than previously identified in the 2002 Supplement. No further environmental review is necessary. Refer also to Responses 4.3.a and 4.3.b.
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Mitigation Measures: No mitigation measures are required. d) Expose sensitive receptors to substantial pollutant concentrations?
Less Than Significant Impact. Sensitive receptors are defined as facilities or land uses that include members of the population that are particularly sensitive to the effects of air pollutants, such as children, the elderly, and people with illnesses. Examples of these sensitive receptors are residences, schools, hospitals, and daycare centers. CARB has identified the following groups of individuals as the most likely to be affected by air pollution: the elderly over 65, children under 14, athletes, and persons with cardiovascular and chronic respiratory diseases such as asthma, emphysema, and bronchitis.
There are no sensitive receptors located in the vicinity of the Airport. As discussed in Response 4.3.a, no new facilities would be constructed as part of the proposed Project. Therefore, Project implementation would result in no greater impacts associated with short-term air emissions than previously identified in the 2002 Supplement. Thus, surrounding sensitive receptors would not be exposed to substantial pollutant concentrations from construction activities associated with the proposed Project. Project implementation would result in no greater impacts associated with construction-related air emissions than previously identified in the 2002 Supplement. No further environmental review is necessary. Refer to Responses 4.3(a) and 4.3(b).
Mitigation Measures: No mitigation measures are required. e) Create objectionable odors affecting a substantial number of people?
Less Than Significant Impact. The proposed Project does not involve any new airside or landside improvements. The Project involves remodeling an existing maintenance building, which would not create objectionable odors affecting a substantial number of people.
The 2002 Supplement concluded that the 2002 Project would result in less than significant impacts regarding the creation of objectionable odors from aircraft operations. The current Project represents approximately 26 percent fewer aircraft operations than the project analyzed in the 2002 Supplement (23,650 annual aircraft operations). Project implementation would result in no greater impacts associated with objectionable odors than previously identified in the 2002 Supplement. Therefore, similar to the 2002 Project, the proposed Project would not create objectionable odors affecting a substantial number of people. No further environmental review is necessary.
Mitigation Measures: No mitigation measures are required.
4.4 BIOLOGICAL RESOURCES.
The findings of the 2002 Supplement (Pages III-36 to III-56) are summarized as follows:
Wetlands. The results of these studies (i.e., wetlands analysis and delineation) show that there are no waters of the United States, including wetlands, located on the project site for the proposed Runway 9-27 extension and the Airport development area.
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The proposed project would have no effect on federally protected wetlands through direct removal, filling, hydrological interruption, or other means. Therefore, no significant impacts to wetlands would occur as a result of the proposed project.
Threatened/Endangered Species. No significant impacts to the sagebrush scrub habitat are expected to occur as a result of the introduction of commercial aircraft service at Mammoth Yosemite Airport. Additionally, no significant natural areas of rare natural communities were located in the project area. Therefore, no impacts to these resources would occur from the proposed project.
No significant impacts to the following wildlife species of special concern or their habitat are expected to occur as a result of the introduction of commercial aircraft service at Mammoth Yosemite Airport:
Sage Grouse; and Mule Deer.
No significant impacts to the following threatened and endangered plant species or their habitat is expected to occur as a result of the introduction of commercial aircraft service at Mammoth Yosemite Airport:
Long Valley milkvetch (Astragalus johnannis-howellii); Mono milkvetch (Astragalus monoensis var. monoensis); and Mono Lake lupine (Lupinus duranii).
No significant impacts to the following threatened and endangered wildlife species or their habitat is expected to occur as a result of the introduction of commercial aircraft service at Mammoth Yosemite Airport:
Peregrine Falcon; Wolverine; Owens Tui Chub; Bald Eagle; and Sierra Nevada Bighorn Sheep.
Raptors. Impacts to raptors could result from either collisions with aircraft, or from disturbance caused by aircraft, which would result in a change in raptor behavior. . . . . No significant effect on nesting or reproductive success was reported in previous analyses as a result of overflights. Other effects included flushing and taking advantage of disturbed prey species for foraging, as well as others. Overall, cited effects to raptors were transient, and did not result in long-term behavior changes.
The proposed project would not cause a substantial reduction in local populations of raptors, waterfowl, or other bird species. In general, bird strikes do not constitute a significant source of mortality for bird populations.
Given the relatively infrequent occurrence of bird-aircraft collisions in areas with substantially higher bird populations, the lack of any bird strikes at Mammoth Yosemite Airport in the last ten years, the small increase in flight operations, the limited amount of time that air carrier aircraft are at low altitudes, the overall low bird densities at the
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proposed project site and project vicinity, and the ability of populations to sustain low levels of annual mortality without a long-term effect, the proposed project will not result in a significant effect to local and migratory bird populations.
Bird Strikes. Given the relatively infrequent occurrence of bird-aircraft collisions in areas with substantially higher bird populations, the lack of any bird strikes at Mammoth Yosemite Airport in the last ten years, the small increase in flight operations, the limited amount of time that air carrier aircraft are at low altitudes, the overall low bird densities at the proposed project site and project vicinity, and the ability of populations to sustain low levels of annual mortality without a long-term effect, the proposed project will not result in a significant effect to local and migratory bird populations.
Disturbance to Nesting Raptors. Disturbance to nesting raptors from the proposed project has been cited as a concern for a potential adverse effect. It was suggested that increased aircraft traffic along the approach and departure routes could create additional disturbance during breeding and nesting periods, which occur from about March 1 to mid summer. Such disturbance might preclude successful reproduction for raptors sensitive to this type of disturbance. . . . . Based upon the analyses below [2002 Supplement Page III-50), no significant effects on raptors are expected.
Other Wildlife. Based on the regional abundance of sagebrush scrub habitat, lack of preferred habitat characteristics, and lack of recorded sightings, the minor loss of sagebrush scrub habitat associated with the proposed project does not represent a significant loss of habitat for the white-tailed hare or the pygmy rabbit. The minor loss in extent of sagebrush scrub habitat associated with the proposed project does not represent a significant loss of foraging or roosting habitat for the following special status wildlife species: northern harrier, golden eagle, loggerhead shrike, spotted bat, and Townsend’s western big-eared bat.
Although osprey, sharp-shinned hawk, Cooper’s hawk, and California gull may occasionally fly over the project site, the minor loss in extent of sagebrush scrub habitat associated with the proposed project does not represent a significant loss of foraging habitat for these species.
No actions associated with the future operation of the proposed project would be expected to further reduce habitat suitability for any of the species discussed above. For these reasons, there is no potential for significant adverse impacts on the above-cited species from the proposed project.
The findings of the 2007 Draft EIS are summarized as follows:
Secondary Noise Impacts. Secondary impacts associated with noise from increased aircraft operations at MMH are not projected to be significant.
Based on the approved forecast, only 2 flights (2 arrivals and 2 departures) are projected to be added to the 53.9 average daily operations during the peak winter month in 2009… the projected average day Leq during the winter peak month in 2009 would be only 0.1 dBA higher than that projected under the No-Action Alternative (47.2 dBA as compared to 47.1 dBA).
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In 2015, eight daily flights (8 arrivals and 8 departures) are projected to be added to the 60.3 average daily GA operations during the winter peak month and two daily flights (2 arrivals and 2 departures) would be added to the 49.7 average daily operations during the summer peak month in 2015…the projected average day Leq during the winter peak month would be only 0.3 dBA higher the that projected under the No-Action Alternative (47.9 dBA as compared to 47.6 dBA). The projected average day Leq during the summer peak month would be only 0.1 dBA higher than that projected under the No- Action Alternative (45.2 dBA as compared to 45.1 dBA).
The projected noise level resulting from operation of Q400aircraft would be substantially lower than many of the existing and projected future aircraft operations at MMH…INM results indicate that approximately 200 of the projected operations by other aircraft types (approach vs. departure, Runway 9 vs. Runway 27) would be louder than the loudest approach by a Q400 aircraft. Approximately 400 types of operations would be louder than the loudest departure by the Q400. Similar to the No-Action Alternative, potential impacts would be limited to a possible increase in premature daily departure of some grouse from the lek in response to any increase in early morning (prior to 9:00 AM) overflights during the lekking season (December through May).
Would the Project: a) Have a substantial adverse effect, either directly or through habitat modifications, on any species identified as a candidate, sensitive, or special status species in local or regional plans, policies, or regulations, or by the California Department of Fish and Game or U.S. Fish and Wildlife Service?
Less Than Significant Impact. The 2002 Project involved 333,000 annual enplanements and 23,650 annual aircraft operations by 757-type aircraft, as well as various physical improvements to the Airport, including runway extension and widening, new fencing, and a new 25,000-SF passenger terminal, among others. As summarized above, the 2002 Supplement concluded that no substantial adverse impacts would occur to any candidate, sensitive, or special status species. Additionally, impacts to vegetation, wildlife, and water resources associated with habitat loss, fencing, aircraft overflights, noise, light, vehicle traffic, human disturbance, bird strikes, disturbance to nesting raptors, and potential groundwater, surface water, and runoff contamination were concluded to be less than significant.
Threatened/Endangered Species. As previously noted, the 2002 Supplement concluded the 2002 Project would not result in substantial adverse impacts on any species identified as a candidate, sensitive, or special status. The proposed Project does not involve any new airside or landside improvements; the Project is limited to remodeling an existing maintenance building. The Project’s construction activities would be confined to the existing maintenance building and existing fencing. Thus, direct impacts to threatened/endangered species associated with habitat loss and new fencing would not occur with the proposed Project.
The proposed Project involves 67,168 annual enplanements and 17,482 annual aircraft operations. Comparatively, the Project represents approximately 80 percent fewer enplanements and approximately 26 percent fewer aircraft operations, than the project analyzed in the 2002 Supplement (333,000 enplanements and 23,650 annual aircraft operations). Project implementation would result in no greater impacts associated with threatened/endangered species than previously identified in the 2002 Supplement and conditions have not changed. Therefore, similar to the 2002 Project, the proposed Project would not have a substantial
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adverse effect on any species identified as a candidate, sensitive, or special status. No further environmental review is necessary.
Raptors. The aircraft operations associated with the 2002 Project could result in impacts to raptors from either collisions with aircraft (i.e., bird strikes), or disturbance caused by aircraft, which would result in a change in raptor behavior; refer to the Bird Strikes and Disturbance to Raptors discussions that follow.
Bird Strikes. The aircraft operations associated with the 2002 Project could result in impacts to raptors (i.e., bird strikes) from collisions with aircraft. The 2002 Supplement concluded the 2002 Project would not cause a substantial reduction in local populations of raptors, waterfowl, or other bird species. In general, bird strikes do not constitute a significant source of mortality for bird populations. The analysis concluded the 2002 Project would not result in a significant effect to local and migratory bird populations given the following factors:
The relatively infrequent occurrence of bird-aircraft collisions in areas with substantially higher bird populations; The lack of any bird strikes at the Airport in the last ten years; The small increase in flight operations; The limited amount of time that air carrier aircraft are at low altitudes; The overall low bird densities at and within the vicinity of the Airport; and The ability of populations to sustain low levels of annual mortality without a long-term effect.
The proposed Project involves 17,482 annual aircraft operations, which could result in impacts to raptors (i.e., bird strikes) from collisions with aircraft. Comparatively, the Project represents approximately 26 percent fewer aircraft operations, than the project analyzed in the 2002 Supplement. Project implementation would result in no greater impacts associated with bird strikes than previously identified in the 2002 Supplement and conditions have not changed. Therefore, the proposed Project would not cause a substantial reduction in local populations of raptors, waterfowl, or other bird species associated with bird strikes. No further environmental review is necessary.
Disturbance to Raptors. The aircraft operations associated with the 2002 Project could result in impacts to raptors from disturbance caused by aircraft, which would result in a change in raptor behavior. The 2002 Supplement concluded that no significant effect on nesting or reproductive success was reported in previous analyses, as a result of overflights. Other effects included flushing and taking advantage of disturbed prey species for foraging. Overall, cited effects to raptors were transient, and did not result in long-term behavior changes. Comparatively, the Project represents approximately 26 percent fewer aircraft operations, than the project analyzed in the 2002 Supplement. Project implementation would result in no greater impacts to forasting or nesting raptors associated with annual aircraft operations than the project analyzed in the 2002 Supplement and conditions have not changed. Therefore, the proposed Project would not have a substantial adverse effect in this regard. No further environmental review is necessary.
Other Wildlife. The 2002 Project involved various physical improvements to the Airport, which would result in habitat loss. The 2002 Supplement concluded substantial adverse impacts on other wildlife would not occur. The proposed Project does not involve any new airside or landside improvements; the Project is limited to remodeling an existing maintenance building. The Project’s construction activities would be confined to the existing maintenance building and existing fencing. Thus, impacts to other wildlife would not occur with the proposed Project.
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Project implementation would result in no greater impacts to other wildlife than previously identified in the 2002 Supplement and conditions have not changed. Therefore, the proposed Project would not have a substantial adverse effect in this regard. No further environmental review is necessary.
Secondary Noise Impacts. The proposed Project would result in less than significant impacts from aircraft flight paths and aircraft noise. As stated in the 2007 Draft EIS, the 2015 projected average day Leq during the winter peak month (47.9 dBA) would be 0.3 dBA higher than under existing (2005) conditions (47.6 dBA). The 2015 projected average day Leq during the summer peak month (45.2 dBA) would be only 0.1 dBA higher than that projected under existing (2005) conditions (45.1 dBA). Additionally, the maximum noise levels at the lek would not change. The projected noise level resulting from operation of Q400 Dash 8 aircraft would be substantially lower than many of the existing and projected future aircraft operations at the Airport. As indicated in the 2007 Draft EIS, approximately 200 of the projected operations by other aircraft types would be louder than the loudest approach by a Q400 Dash 8 aircraft. Approximately 400 types of operations would be louder than the loudest departure by the Q400 Dash 8.
As stated in the 2007 Draft EIS, potential impacts would be limited to a possible increase in premature daily departure of some grouse from the lek (mating arena) in response to any increase in early morning (prior to 9:00 AM) overflights during the lekking season (December through May). However, the proposed Q400 Dash 8 aircraft would have fewer noise impacts than the existing and projected future aircraft utilized by the Airport. Therefore, the proposed Project would not result in substantial adverse effects to wildlife and plant species in this regard.
Mitigation Measures: No mitigation measures are required. b) Have a substantial adverse effect on any riparian habitat or other sensitive natural community identified in local or regional plans, policies, regulations or by the California Department of Fish and Game or U.S. Fish and Wildlife Service?
No Impact. The closest riparian habitat is located approximately one mile north of the Airport, along Hot Creek.33 Therefore, as the proposed Project does not involve any new airside or landside improvements and is limited to remodeling an existing maintenance building, the proposed Project would not have a substantial adverse effect on riparian habitat. No significant natural areas of rare natural communities are located in the Project area.34 Project implementation would not impact any riparian habitat or other sensitive natural communities.
Mitigation Measures: No mitigation measures are required. c) Have a substantial adverse effect on federally protected wetlands as defined by Section 404 of the Clean Water Act (including, but not limited to, marsh, vernal pool, costal, etc.) through direct removal, filling, hydrological interruption, or other means?
No Impact. There are no waters of the United States, including wetlands, located within the Airport development area.35 The proposed Project would have no effect on federally protected wetlands through direct removal, filling, hydrological interruption, or other means.
33 2002 Supplement, Page III-48.
34 Ibid., Page III-48.
35 Ibid., Page III-36.
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Mitigation Measures: No mitigation measures are required. d) Interfere substantially with the movement of any native resident or migratory fish or wildlife species or with established native resident or migratory wildlife corridors, or impede the use of native wildlife nursery sites?
No Impact. The migration corridor for mule deer from the Round Valley herd passes immediately south of the Mammoth Yosemite Airport. The proposed Project does not involve any new improvements; rather the Project is limited to remodeling an existing maintenance building. The Project’s construction activities would be confined to the existing maintenance building and existing fencing. Therefore, Project implementation would not interfere with the movement of mule deer.
The Hot Creek Fish Hatchery is located approximately 1.0 mile north of the Airport, within a privately-owned fishing camp (Hot Creek Ranch). The Project’s construction activities would be confined to the existing maintenance building and existing fencing. Therefore, the proposed Project would have not directly impact the Hot Creek Fish Hatchery.
Groundwater flows travel in an easterly direction throughout the Project vicinity. The Hot Creek headsprings are located northwest of the Airport. As concluded in the 2002 Supplement, in the unlikely event of a fuel truck spill along the travel route and if the spill migrated to the ground water, ground water flow would carry any seepage away from the Hot Creek Hatchery springs. Thus, neither groundwater flow or water quality would be affected by the proposed Project. Therefore, the proposed Project would not interfere with or impede the use of the Hot Creek Fish Hatchery.
Mitigation Measures: No mitigation measures are required. e) Conflict with any local policies or ordinances protecting biological resources, such as tree preservation policy or ordinance.
Less Than Significant Impact. The Town has adopted several ordinances that protect biological resources. Town Code Chapter 6.24, Feeding of Wildlife Prohibited, specifies that no person shall feed or in any manner provide food for nondomesticated animals, Code Chapter 8.12, Refuse Disposal, requires proper refuse disposal to eliminate the availability of refuse for wildlife. Through the permit application process, the proposed passenger terminal would be reviewed by the Town to confirm consistency with these ordinances protecting biological resources. With the Town’s discretionary review of the proposed improvements through the established procedures, implementation of the Project would not conflict with ordinances protecting biological resources and a less than significant impact would occur in this regard.
Mitigation Measures: No mitigation measures are required. f) Conflict with the provisions of an adopted Habitat Conservation Plan, Natural Community Conservation Plan, or other approved local, regional, or state habitat conservation plan?
Less Than Significant Impact. Conservation and recovery plans for areas in the vicinity of the Town and Airport property include the Owens Basin Wetland and Aquatic Species Recovery Plan, the Mule Deer Herd Management Plans, and the Greater Sage-Grouse Conservation Plan for Nevada and Eastern California. Airport property is not located within the jurisdiction of any of these plans. Thus, implementation of the proposed Project would not conflict with any
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adopted Habitat Conservation Plans, Natural Community Conservation Plan, or other approved local, regional, or state habitat conservation plans.
Mitigation Measures: No mitigation measures are required.
4.5 CULTURAL RESOURCES.
The findings of the 1997 Subsequent EIR are summarized as follows:
Cultural resource record search and studies have been conducted for the Runway 9-27 extension, the construction of the crosswind runway, the commercial development area, and the airport development area to update the information available in the 1986 Report. . . . . this record search and cultural resource study shows that there are no known cultural resources included in the proposed Runway 9-27 extension area, the commercial development area, or the airport development areas.
The findings of the 2007 Draft EIS are summarized as follows:
There are no historical, architectural, archaeological, or cultural resources contained within the Area of Potential Affect (APE); therefore, FAA has determined that there would be no effect on these resources under either the No-Action or Proposed Action alternatives. The State Historic Preservation Officer concurred with the FAA’s determination by letter dated March 12, 2007.
Would the Project: a) Cause a substantial adverse change in the significance of a historical resource as defined in CEQA Guidelines '15064.5?
No Impact. According to the 2007 Draft EIS, the FAA has determined that the APE is made up of a combination of the year 2015 Community Noise Equivalent Level (CNEL) 65 dBA noise contour and the Airport boundary. The State Historic Preservation Office (SHPO) concurred with the FAA’s proposed APE.
The Project’s construction activities would be confined to the existing maintenance building and existing fencing, which are located within the defined APE. The Project does not involve any earth removal or disturbance. There are no historical, architectural, archaeological, or cultural resources contained within the APE.36 Therefore, Project implementation would not cause a substantial adverse change in the significance of a historical resource, archaeological, or paleontological resource, or unique geologic feature. Mitigation Measures: No mitigation measures are required. b) Cause a substantial adverse change in the significance of an archaeological resource pursuant to CEQA Guidelines Section 15064.5?
No Impact. Refer to Response 4.5(a).
Mitigation Measures: No mitigation measures are required.
36 2007 Draft EIS, Page 5-26.
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c) Directly or indirectly destroy a unique paleontological resource or site or unique geologic feature?
No Impact. Refer to Response 4.5(a).
Mitigation Measures: No mitigation measures are required. d) Disturb any human remains, including those interred outside of formal cemeteries?
No Impact. The proposed Project does not involve any earth removal or disturbance. Therefore, Project implementation would not disturb any human remains, including those interred outside of formal cemeteries.
Mitigation Measures: No mitigation measures are required.
4.6 GEOLOGY AND SOILS.
The findings of the 1986 EIR/EA (Pages 7, and Pages 46 to 51) are summarized as follows:
Development of residential properties and public facilities in an area of known seismic and volcanic hazards may expose residents to safety hazards.
During earthwork operations, most sites will consist of disturbed, exposed soil surfaces subject to significant erosion hazards in the event of a major storm event. Erosion from exposed soil surfaces could result in the direct loss of valuable topsoil materials, as well as secondary impacts associated with the deposition of silt and sediment on adjacent downstream properties.
Potential long-term impacts associated with soil disturbances and land transformations can be significantly mitigated by appropriate design, construction, and stabilization considerations.
The entire Eastern Sierra region is seismically active, and there are at least four major active or potentially active faults within a 25-mile radius of the Mammoth/June Lake Airport [i.e., Mammoth Yosemite Airport].
There is a high probability that seismic events in the magnitude range of 6.0 to 7.0 will occur in the airport planning area within a 25-year time period. Based on previous events, fault rupture will most likely occur along defined and documented fault lines. . . . . In the event of catastrophic earthquake, developments in the planning area could suffer extensive property damage and/or personal injuries or casualties.
The most likely volcanic hazard would be associated with an eruption of one of the dormant rhyolite volcanoes. . . . .
The primary conclusion to be drawn from the events of the summers of 1980 and 1981 is that conventional one- and two-story, wood-frame structures can withstand considerable seismic forces when designed and constructed in accordance with modern Uniform Building Code Standards.
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The findings of the 2002 Supplement (Page III-72) are summarized as follows:
. . . . . the proposed project would not result in substantial soil erosion or the loss of top soil, nor would it cause soil to become unstable and result in on- or off-site landslide, lateral spreading, subsidence, liquefaction, or collapse. Consequently the project would not have a significant impact on soils/land transformation.
Would the Project: a) Expose people or structures to potential substantial adverse effects, including the risk of loss, injury, or death involving:
1) Rupture of a known earthquake fault, as delineated on the most recent Alquist-Priolo Earthquake Fault Zoning Map issued by the State Geologist for the area or based on other substantial evidence of a known fault? Refer to Division of Mines and Geology Special Publication 42.
Less Than Significant Impact. Figure 16, Geologic Hazard Zones, of the 1986 EIR/EA, illustrates the locations of the faults in the Project region. As indicated in Figure 16, no Alquist- Priolo Earthquake Fault Zone traverses the Airport property. Therefore, Project implementation would result in less than significant impacts associated with the exposure of people or structures to potential substantial adverse effects involving fault rupture. No further environmental review is necessary.
Mitigation Measures: No mitigation measures are required.
2) Strong seismic ground shaking?
Less Than Significant Impact. The 1986 Project involved major development and expansion of the Airport terminal area, including additional aircraft support facilities, a new passenger terminal, an airport hotel, and extensive infrastructure improvements. The 1986 EIR/EA concluded there are at least four major active or potentially active faults within a 25-mile radius of the Airport and that development in the Airport planning area could suffer extensive property damage and/or personal injuries or casualties. The proposed Project does not involve any new airside or landside improvements and is limited to remodeling an existing maintenance building. Additionally, the current Project represents approximately 42 percent fewer aircraft operations than the project analyzed in the 1986 EIR/EA (30,000 annual aircraft operations by 1995). The proposed Project would not expose people/structures to substantial impacts involving strong seismic ground shaking. Project implementation would result in no greater impacts involving strong seismic ground shaking than would be true for any development in the Project area, or than previously identified in the 1986 EIR/EA, and conditions have not changed. The Project is subject to compliance with Code Section 15.24.020, Seismic Design - Uniform Building Code - Section 2333(b), which requires that all structures be designed to the requirements of Seismic Zone 4, as defined in the Uniform Building Code (UBC). Adherence to standard engineering practices and Town Code requirements relative to seismic and geologic hazards would minimize potential impacts. Therefore, similar to the 1986 Project, the proposed Project would result in less than significant impacts associated with the exposure of people or structures to potential substantial adverse effects involving strong seismic ground shaking. No further environmental review is necessary.
Mitigation Measures: No mitigation measures are required.
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3) Seismic-related ground failure, including liquefaction?
Less Than Significant Impact. Liquefaction of cohesionless soils can be caused by strong vibratory motion due to earthquakes. Liquefaction is characterized by a loss of shear strength in the affected soil layers, thereby causing the soils to behave as a viscous liquid.
The 2002 Supplement concluded the 2002 Project would not result in on- or off-site liquefaction or landslides. No new facilities would be constructed as part of the proposed Project and no new significant environmental impacts associated with liquefaction or landslides would occur. Therefore, Project implementation would result in less than significant impacts associated with the exposure of people or structures to potential substantial adverse effects involving liquefaction and landslides. No further environmental review is necessary.
Mitigation Measures: No mitigation measures are required.
4) Landslides?
No Impact. Refer to Response 4.6(a)(3).
Mitigation Measures: No mitigation measures are required. b) Result in substantial soil erosion or the loss of topsoil?
Less Than Significant Impact. The 2002 Project involved various physical improvements to the Airport, including runway extension and widening, new fencing, and a new 25,000-SF passenger terminal, as well as 200 acres of grading. The 2002 Supplement concluded the 2002 Project would not result in substantial soil erosion or the loss of topsoil. The proposed Project would not involve any ground-disturbing changes or new construction. Project implementation would result in no greater impacts involving soil erosion or the loss of topsoil than previously identified in the 2002 Supplement and conditions have not changed. Therefore, Project implementation would not result in substantial soil erosion or the loss of topsoil. It is noted the Project would be subject to compliance with the drainage and erosion design standards specified in Code Section 12.08.090. The Project would be subject to compliance with the requirements set forth in the National Pollutant Discharge Elimination System (NPDES) Storm Water General Construction Permit for construction activities; refer to Response 4.8(a). No further environmental review is necessary.
Mitigation Measures: No mitigation measures are required. c) Be located on a geologic unit or soil that is unstable, or that would become unstable as a result of the project, and potentially result in an on-site or off-site landslide, lateral spreading, subsidence, liquefaction or collapse?
Less Than Significant Impact.
Volcanic Activity
The 1986 Project involved major development and expansion of the Airport terminal area. The 1986 EIR/EA concluded development of public facilities in an area of known volcanic hazards could expose residents to safety hazards. The proposed Project does not involve any new improvements and is limited to remodeling an existing maintenance building. Additionally, the
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current Project represents approximately 42 percent fewer aircraft operations than the project analyzed in the 1986 EIR/EA (30,000 annual aircraft operations). Project implementation would not expose people/structures to substantial impacts involving volcanic activity. Project implementation would result in no greater impacts involving volcanic activity than would be true for any development in the Project area, or than previously identified in the 1986 EIR/EA, and conditions have not changed. The Project would be subject to compliance with the emergency response plan prepared for the Airport. Therefore, similar to the 1986 Project, the proposed Project would result in less than significant impacts associated with the exposure of people or structures to potential substantial adverse effects involving volcanic activity. No further environmental review is necessary.
Unstable Soils
The 2002 Supplement concluded the 2002 Project would not result in on- or off-site landslides, lateral spreading, subsidence, liquefaction, or collapse. No new facilities would be constructed as part of the proposed Project and no new significant environmental impacts associated with landslides, lateral spreading, subsidence, liquefaction, or collapse would occur. The proposed Project would not be located on a geologic unit or soil that is unstable, or that would become unstable as a result of the Project, and potentially result in an on-site or off-site landslide, lateral spreading, subsidence, liquefaction, or collapse. No further environmental review is necessary.
Mitigation Measures: No mitigation measures are required. d) Be located on expansive soil, as defined in Table 18-1-B of the Uniform Building Code (1994), creating substantial risks to life or property?
No Impact. Figure 14, Area Landforms, of the 1986 EIR/EA illustrates the major landforms in the Airport area. According to Figure 14, the Airport primarily involves the Alluvial landform, which is described as unconsolidated sediments and detrital material deposited by water transport. Additionally, no new facilities would be constructed as part of the proposed Project. The Project’s construction activities would be confined to the existing maintenance building and existing fencing. Extensive geotechnical studies have been conducted throughout the Airport, including in the vicinity of the Terminal building. The soils consist of clean sands, gravels, and cobbles and are very pervious.37 Therefore, Project implementation would not create substantial risks to life or property involving expansive soils. No further environmental review is necessary.
Mitigation Measures: No mitigation measures are required. e) Have soils incapable of adequately supporting the use of septic tanks or alternative wastewater disposal systems where sewers are not available for the disposal of wastewater?
Less Than Significant Impact. The Project involves remodeling an existing maintenance building for use as a passenger terminal, which would generate wastewater. The average sewage effluent produced by each passenger will be 1.5 gallons per day (gpd). It is estimated that there will be nine employees in the temporary terminal and that the average daily sewage
37 Written correspondence from Reinard W. Bradley, Consulting Airport Engineer, to Mr. Raymond Jarvis, Town of Mammoth lakes Director of Public Works, dated February 13, 2008.
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effluent produced per employee is 15 gallons. The design daily sewage discharge for the terminal would conservatively be 1,767 gallons per day.38
The existing facility has a septic tank and leaching lines that were installed in accordance with Mono County Design Standards. The size and location of the existing septic tank and leach lines are unknown at this time. The Town will install locator wires into the lines, locate the septic tank, and uncover the manholes. The size of the tank would be measured and if a larger tank is required, the construction contract would be modified and a new septic tank of the required size will be installed.
Extensive geotechnical studies have been conducted throughout the Airport, including in the vicinity of the Terminal building. The soils consist of clean sands, gravels, and cobbles and are very pervious. All of the drainage from the existing aircraft parking apron, which covers approximately 12 acres, is collected and piped to a trench located immediately north of the existing septic system. This trench is approximately 15 feet wide, 4 feet deep, and 120 feet long, and it has accommodated all of the runoff from this pavement section and has never been observed to reach capacity. Observations on the airfield show that storm water that drains off from the paved runway surfaces, even in the heavy rains from thunderstorms, runs off the runway paved surface (100 foot wide) and disappears into the soil at the edge of the runway by infiltration.39 None of the storm water has been observed to reach the swale that is located approximately 150 feet from the edge of the runway. These observations and tests confirm the high coefficient of permeability of the soils in this area. Therefore, no additional leach lines would be required. No further environmental review is necessary.
Mitigation Measures: No mitigation measures are required.
4.7 HAZARDS AND HAZARDOUS MATERIALS.
The findings of the 1986 EIR/EA (Pages 23, 51, and 93) are summarized as follows:
Development within the vicinity of the Mammoth/June Lake Airport may adversely affect the safety of air navigation and represent hazards to residents and the general public.
The Mammoth/June Lake Airport is the primary aircraft access point for Mono County. Disruption of airport activities during a major seismic or volcanic event would hamper emergency assistance efforts, medical evacuation, and could significantly lengthen emergency response times.
Existing emergency fire protection and crash/rescue facilities at the airport are substandard. Airport operations necessarily involve relatively large storage tanks of highly flammable fuels and oils.….. The airport is within the service area of the Long Valley Fire Protection District, which houses its major fire suppression equipment almost eight miles away. The main station of the Mammoth Lakes Fire Department is also about eight miles distant.
The entire Airport Land Use Plan is basically intended to function as a general mitigation for aircraft-related safety and public welfare hazards. The Land Use Policy Plan
38 Ibid.
39 Ibid.
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presented in Appendix B (of the 1986 EIR/EA) contains . . . . specific provisions and measures for the various aircraft operation zones. . . (i.e., Airport Safety Zone: Figure 11 of the 1986 EIR/EA, Airport Overflight and Traffic Pattern Zone: Figure 12 of the 1986 EIR/EA, and Airport Height Restrictions/ACZP Zone: Figure 13 of the 1986 EIR/EA.
The findings of the 1997 Subsequent EIR (Page 19) are summarized as follows:
The proposed commercial development areas and airport development areas are located within the Sideline Safety Zone (Zone No. 5). The proposed population densities in these areas somewhat exceed those recommended in the Airport Land Use Planning Handbook. The low aircraft operations at this airport reduce any risk to development in these areas.
The findings of the 2007 Draft EIS (Page 5-58, 5-62, and 5-96) are summarized as follows:
Since no construction activities would occur under either the No-Action or Proposed Action alternatives, neither alternative has the potential to effect sites or facilities known to contain environmental contamination. The implementation of the Proposed Action would not substantially alter the types of hazardous materials and other regulated materials currently used at the Airport. However, the amounts of aviation fuel used would increase in the future due to the forecasted increase in the number of GA and air carrier aircraft operations at the Airport. This increase would not result in a significant impact.
Aircraft deicing would be required during the winter for approximately 33 percent of the Horizon Air flights (approximately five aircraft per week). Each deicing event would require approximately 50 gallons or less of deicing fluid, which equals a volume of approximately 250 gallons per week. The existing onsite collection basin has sufficient holding capacity to store the spent deicing fluid until it can be collected for disposal. Spent deicing fluid would be transported off site for disposal or recycling. There would be no impact from the Proposed Action on groundwater quality or supply.
The level of emergency assistance and fire protection at the airport must be extensively upgraded in the interests of the public safety and welfare. Proposed airport project improvements include the installation of crash/fire/rescue (cfr) building with emergency response equipment and the installation of a water supply, storage, and distribution system capable of providing adequate fire suppression flows. In addition, future airport development plans should provide for standby electrical generation equipment.
Would the Project: a) Create a significant hazard to the public or the environment through the routine transport, use, or disposal of hazardous materials?
Less Than Significant Impact. The 1986 Project involved 53,400 annual aircraft operations by 1995. The 1986 EIR/EA concluded that the forecasted increase in aircraft operations at the Airport would not result in a significant impact involving hazardous materials. The current proposal involves 17,482 annual aircraft operations by 2015. These aircraft operations could increase the use of maintenance and safety vehicles, as well as the use and treatment of deicing substances during the winter ski season. Additionally, the storage and transfer of
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aviation fuels and fluids would create a potential for spill incidents. Thus, the forecasted the Airport aircraft operations would involve the routine transport, use, and disposal of hazardous materials and could result in an accidental release of hazardous materials. Project implementation would not substantially alter the Airport activities, or the types of hazardous materials and other regulated materials currently used at the Airport. The existing fueling facilities are compliant with applicable regulations and compliance with the Airport’s Spill Prevention Control and Countermeasure (SPCC) Plan would be required.40 The existing on-site collection basin has sufficient holding capacity to store the spent deicing fluid until it can be collected and transported off site for disposal/recycling.41 Compliance with an approved Deicing Plan in accordance with FAA’s AC 150/5200-30A42 guidelines would be required. Additionally, the current Project represents approximately 42 percent fewer aircraft operations than the project analyzed in the 1986 EIR/EA. Project implementation would result in no greater impacts involving hazardous materials than previously identified in the 1986 EIR/EA. Therefore, the Project’s forecast aircraft operations would not create a significant hazard to the public or the environment through the routine transport, use, or disposal of hazardous materials, or the accidental release of hazardous materials. No further environmental review is necessary.
Mitigation Measures: No mitigation measures are required. b) Create a significant hazard to the public or the environment through reasonably foreseeable upset and accident conditions involving the release of hazardous materials into the environment?
Less Than Significant Impact. Refer to Response 4.7(a) and 4.8(a).
Mitigation Measures: No mitigation measures are required. c) Emit hazardous emissions or handle hazardous or acutely hazardous materials, substances, or waste within one-quarter mile of an existing or proposed school?
No Impact. There are no schools located within 0.25-mile of the Airport property. The proposed Project would not emit or handle hazardous or acutely hazardous materials, substances, or waste within 0.25-mile of an existing or proposed school.
Mitigation Measures: No mitigation measures are required. d) Be located on a site which is included on a list of hazardous materials sites compiled pursuant to Government Code Section 65962.5 and, as a result, would it create a significant hazard to the public or the environment?
No Impact. An area known to contain environmental contamination exists at the Airport. In 2002, a subsurface environmental investigation was conducted that indicated the presence of petroleum hydrocarbon contamination in soil and groundwater beneath most of the area near the former hangar.43 The proposed Project does not involve any new airside or landside
40 The SPCC Plan establishes procedures, methods, equipment, and other requirements to prevent discharge of oil or other hazardous materials from the airport.
41 2007 Draft EIS, Page 5-67.
42 This FAA advisory circular (AC) provides guidance to assist airport owners/operators in the development of an acceptable airport snow and ice control program and on appropriate field condition reporting procedures.
43 2007 Draft EIS, Page 4-52.
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improvements. Since the Project is limited to remodeling an existing maintenance building, the Project’s construction activities would be confined to the existing maintenance building and existing fencing. The proposed Project would not disturb the contaminated area or involve a site which is included on a list of hazardous materials sites. Therefore, the Project would not create a significant hazard to the public or the environment in this regard.
Mitigation Measures: No mitigation measures are required. e) For a project located within an airport land use plan or, where such a plan has not been adopted, within two miles of a public airport or public use airport, would the project result in a safety hazard for people residing or working in the project area?
Less Than Significant Impact. The Airport Land Use Plan (ALUP) for the Airport was evaluated in the 1986 EIR/EA and adopted in May 1986. Under the ALUP, land use policies were developed to protect public welfare and the safety of aircraft operations including policies regarding airport safety zones, overflight zones and traffic patterns, height restrictions, and noise. The ALUP established standards regarding structures, objects, and obstructions within the Airport Safety Zone, Airport Overflight and Traffic Pattern Zone, and Airport Height Restrictions Zone (ACZP).
The 1986 EIR/EA analyzed impacts associated with 53,400 annual aircraft operations and concluded compliance with the ALUP would function as a general mitigation for aircraft-related safety and public welfare hazards, reducing potential impacts to less than significant.44 The proposed Project does not involve any new airside or landside improvements. The Project involves remodeling an existing maintenance building for use as a passenger terminal. The proposed remodeling would be limited to new windows, doors, and cross-gabled entryways. No changes to the structure’s height (30 feet) or mass are proposed. Additionally, the existing fence at the terminal would be modified in its same location (i.e., gates added). The Project’s construction activities would be confined to the existing maintenance building and existing fencing. Since no new structures, objects, or obstructions are proposed, the Project would be in compliance with the ALUP regarding the Airport Safety Zone, Airport Overflight and Traffic Pattern Zone, and Airport Height Restrictions Zone. Additionally, the current Project represents approximately 42 percent fewer aircraft operations than analyzed in 1986 EIR/EA. It is further noted all development proposals within the Airport planning area would be reviewed by the ALUC to determine potential impacts on aircraft navigation and safety.45 Therefore, similar to the 1986 Project, the proposed Project would result in less than significant impact potential safety hazards for people working or traveling in the Project area. No further environmental review is necessary.
The 1997 Subsequent EIR identified six safety zones around the Airport based on Caltrans Division of Aeronautics’ Airport Land Use Planning Handbook (December 1993); refer to Plate No. 14, ALUC Airport Safety Zone Plan, of the 1997 Subsequent EIR. The safety zones were established for the purpose of protecting the public from accidents on or in the vicinity of the Airport. The proposed commercial and Airport development areas were identified within the Sideline Safety Zone (Zone No. 5), with a recommended population density of 40 to 60 persons per acre. The 1997 Subsequent EIR concluded that although the proposed population densities in Airport development areas within Zone No. 5 somewhat exceed the densities recommended
44 1986 EIR/EA, Page 94.
45 Ibid., Page 95.
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in the Airport Land Use Planning Handbook, the low level of aircraft operations at the Airport reduce any risk to development in these areas.46
No new facilities would be constructed as part of the proposed Project. The Project’s construction activities would be confined to the existing maintenance building and existing fencing. According to Plate No. 14, the existing maintenance building (i.e., proposed passenger terminal) is located in the Sideline Safety Zone (Zone No. 5). Additionally, the Project involves a projected 17,482 annual aircraft operations, which represent approximately 49 percent fewer aircraft operations than the project analyzed in the 1997 Subsequent EIR (34,430 annual aircraft operations). Project implementation would result in no greater impacts involving Airport safety hazards than previously identified in the 1997 Subsequent EIR and conditions have not changed. Therefore, similar to the 1997 Project, the proposed Project would result in less than significant impact involving potential Airport safety hazards.
The 1986 EIR/EA concluded existing emergency assistance and fire protection facilities at the Airport were inadequate and required extensive upgrades. Since 1986, upgrades to the Airport’s emergency assistance and fire protection facilities have been implemented. More specifically, the Airport Emergency Plan (approved by the FAA on September 26, 2005) consists of two plans: the Town’s Emergency Operations Plan (EOP) for major incidents; and the Airport Emergency Plan (AEP). The Town’s EOP covers the mitigation, preparedness, response and recovery from major incidents or natural disasters. Details regarding resources, command and control, and contacts are addressed. During an incident at the Airport, if Airport resources are insufficient, the Airport would contact the countywide dispatch center for emergency services. The AEP ensures the safety and service for people and the community. Under the AEP, the Airport has authority to administer the Airport Rules and Regulations and has provided an Airport Manager/Staff to insure the safe and efficient operation of the Airport. The AEP’s area of control is incidents occurring on the Airport. The first response to an emergency at the Airport would be the Aircraft Rescue and Fire Fighting (ARFF) vehicle. The AEP further details the following:
Action Plan; Alert, Warning, and Public Information and Communications; Resources; Situations Requiring Outside Resources; Airport Special Conditions; Incident Investigatory and Recovery Phase; and Training.
The Project involves 17,482 annual aircraft operations, which would generate a demand for emergency assistance and fire protection facilities. Continued implementation of the Airport’s AEP would ensure that Project implementation would not result in a significant safety hazard for people residing or working in the Project area.
Mitigation Measures: No mitigation measures are required. f) For a project within the vicinity of a private airstrip, would the project result in a safety hazard for people residing or working in the project area?
Less Than Significant Impact. Refer to Response 4.7(e).
46 1997 Subsequent EIR, Page 19.
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Mitigation Measures: No mitigation measures are required. g) Impair implementation of or physically interfere with an adopted emergency response plan or emergency evacuation plan?
Less Than Significant Impact. The Airport is the primary aircraft access point for Mono County. The 1986 EIR/EA concluded that disruption of Airport activities during a major seismic or volcanic event would hamper emergency assistance efforts, medical evacuation, and could significantly lengthen emergency response times. Project implementation would result in no greater impacts associated with emergency response than previously identified in the 1986 EIR/EA. Therefore, Project implementation would result in less than significant impacts in this regard.
Mitigation Measures: No mitigation measures are required. h) Expose people or structures to a significant risk of loss, injury or death involving wildland fires, including where wildlands are adjacent to urbanized areas or where residences are intermixed with wildlands?
Less Than Significant Impact. Fire hazard and risk are measured by the amount of fuel available to burn at any given time in any given area, and the likelihood that an ignition would occur. The Airport’s location relative to the surrounding vegetation (Inyo National Forest and Bureau of Land Management) increases the Airport’s susceptibility to wildland fires. Fire hazard severity has been mapped by the California Department of Forestry (CDF). The Town and surrounding area have been rated as having a very high fire potential. Thus, implementation of the proposed Project could expose people or a structure to risk involving wildland fires, as would be true for any development in the Project area.
As discussed in Response 4.7(e), the first response to an emergency at the Airport would be the Aircraft Rescue and Fire Fighting (ARFF) vehicle. The Airport is located in the Long Valley Fire Protection District, one of 11 local volunteer fire protection districts that provide fire protection throughout Mono County. Mutual aid agreements with surrounding counties extend the area of coverage in times of need. The Project would be subject to compliance with the Town’s Wildland Safety Standards, including those established for emergency access, signing and building, private water supply reserves for fire use, and vegetation modification. The proposed Project is subject to compliance with the relevant standards specified in Town Code Section 17.28.620, Development Standards (Airport Zone) and Code Chapter Chapter 18.02, Mammoth Lakes Airport Rules and Regulations. Through the project review process, the proposed Project would be reviewed by the Long Valley Fire Protection District and the Town, in conjunction with the application for a Building Permit, in order to ensure that Code regulations are met, adequate fire protection is provided, and fire hazards are minimized. Project implementation would result in a less than significant impact regarding the exposure of people or structures to a significant risk involving wildland fires, following compliance with Code and Fire Protection District requirements.
Mitigation Measures: No mitigation measures are required.
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4.8 HYDROLOGY AND WATER QUALITY.
The findings of the 2002 Supplement (Pages III-79 to 81), are summarized as follows:
The existing drainage from the runways and taxiways begins with sheet flow from the pavement to the infield areas of the Airport and then infiltration into the ground. The drainage from the aircraft parking apron, access roads, and other paved areas begins as sheet flow to drainage inlet structures. The effluent is then piped to an infiltration trench located east of the current ground vehicle building where it infiltrates into the ground. No water has been observed flowing beyond the Airport boundary during heavy rain storms.
While it is not anticipated that a large quantity of deicing fluids will be used on aircraft, it will be necessary that facilities be available on site when needed. . . . . Deicing, when required, would generally be accomplished by the use of glycol diluted to a 50 percent solution by water.
The passenger terminal facility and supporting employees would increase the demand on subsurface water resources. Fire protection requirements are the dominant factor in the design of the proposed water supply and transmission facilities. . . . . The estimated maximum daily demand for water generated by the Airport terminal complex was 16,000 gallons.
The estimated maximum annual water demand for the Airport terminal complex has been calculated to be 17.92 acre-feet (1 acre-foot = 326,308 gallons).
Consumptive use of up to 2,700 acre-feet per day would not significantly impact the flows from the headsprings. Maximum annual water demand for the terminal building facility is projected to be less than 18 acre-feet per year, well below the 2,700 acre-feet per day available.
Impervious surfaces increase the volume of stormwater runoff and may effect the relative quality of surface drainage. Runoff from impervious aeronautical surfaces may contain increased quantities of oils, grease, deicing fluid, and other complex hydrocarbon compounds. Construction of a new terminal building and automobile parking facilities would also result in an increase in runoff.
All existing pavement and the pavement for the future runway extension and taxiways would drain into the surrounding ground as they presently do. All new pavements for the commercial aircraft parking apron, automobile parking lot, and terminal roadway would be designed such that all the drain water from these areas would be collected in inlets and pipe structures. These drain waters would be carried through an oil/water separator to separate any oils from the stormwater. The resulting stormwater would then be discharged into leaching trenches or leaching fields.
All aircraft would be deiced at the same location on the commercial airline apron. The area on which the aircraft would park during the deicing operations would be graded such that all of the water from this area would be collected at one drop inlet. The pipes from this inlet would be constructed such that in normal operations, without any deicing fluid, the stormwater runoff would be discharged into the oil/water separator. When deicing operations are being performed, the valves would be set such that all of the
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deicing fluids would be diverted to a holding tank. The runoff would be collected in the holding tank and removed from the site and disposed of in a suitable manner. Best Management Practices (BMPs), such as not allowing oil changes and/or car maintenance on-site, would be used to mitigate potential water quality impacts.
The proposed project would have no significant environmental impacts on hydrology, water supply, or water quality because after meeting all the above mentioned (Page III- 81 of the 2002 Supplement) design requirements, it would not create or contribute runoff, which would exceed the capacity of existing or planned storm-water drainage systems or provide substantial additional sources of polluted runoff. There would be no violation of applicable water quality standards or water discharge requirements and it would not substantially deplete groundwater resources or interfere with groundwater recharge such that there would be a net deficit in aquifer volume or a lowering of a local groundwater table level. The project would not impede or redirect flood flows or place housing within a 100-year flood hazard area.
The findings of the 2007 Draft EIS (Page 5-62) are summarized as follows:
The Under the No-Action Alternative, aircraft operations at the Airport would increase slightly over time when compared to the existing conditions. As a result, there would be little change in the quality and quantity of stormwater runoff or groundwater supplies in the vicinity of the Airport.
. . . . . Aircraft deicing would be required during the winter for approximately 33 percent of the Horizon Air flights (approximately five aircraft per week). . . . . The existing onsite collection basin has sufficient holding capacity to store the spent deicing fluid until it can be collected for disposal. Spent deicing fluid would be transported off site for disposal or recycling.
In 2015, the Proposed Action would have no impact on stormwater runoff, surface water quality, or groundwater quality or supply in comparison to the No-Action Alternative.
Would the Project: a) Violate any water quality standards or waste discharge requirements?
Less Than Significant Impact. As authorized by the Clean Water Act, the National Pollutant Discharge Elimination System (NPDES) permit program controls water pollution by regulating point sources that discharge pollutants into waters of the United States. Point sources are discrete conveyances such as pipes or man-made ditches. Individual homes that are connected to a municipal system, use a septic system, or do not have a surface discharge do not need an NPDES permit; however, industrial, municipal and other facilities must obtain permits if their discharges go directly to surface waters. The NPDES permit program is administered by the California Regional Water Quality Control Board. There are nine Regional Water Quality Control Boards (RWQCB), which are responsible for development and enforcement of water quality objectives and implementation plans. The Airport property is located in the jurisdiction of the Lahontan RWQCB.
Impacts related to water quality typically range over three different periods: 1) during the earthwork and construction phase, when the potential for erosion, siltation, and sedimentation would be the greatest; 2) following construction, prior to the establishment of ground cover,
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when the erosion potential may remain relatively high; and 3) following completion of the Project, when impacts related to sedimentation would decrease markedly, but those associated with urban runoff would increase.
Short-Term Construction
Dischargers whose projects disturb 1.0 or more acres of soil or whose projects disturb less than 1.0 acre, but are part of a larger common plan of development that in total disturbs 1.0 or more acres, are required to obtain coverage under the General Permit for Discharges of Storm Water Associated with Construction Activity (Construction General Permit, 99-08-DWQ). Construction activity subject to this permit includes clearing, grading and disturbances to the ground such as stockpiling or excavation.
The Construction General Permit requires the development and implementation of a Storm Water Pollution Prevention Plan (SWPPP). Section A of the Construction General Permit describes the elements that must be contained in a SWPPP. Short-term impacts to storm water quality generally occur from construction and associated earth moving, and increased pollutant loadings would occur immediately offsite. The Project’s construction activities would be confined to the existing maintenance building and existing fencing. The Project does not involve any earth removal or disturbance, thus, would not disturb 1.0 or more acres of soil. Therefore, the Project would not be required to obtain coverage under the Construction General Permit. Code Section 12.08.090, Drainage and Erosion Design Standards, outlines the drainage and erosion design standards that are required by the Town, beyond the RWQCB requirements. Following compliance with the relevant provisions of the NPDES and Code Section 12.08.090, Project implementation would not violate any water quality standards or waste discharge requirements associated with construction activities.
Long-Term Operations
The primary objectives of the municipal storm water program requirements are to effectively prohibit non-storm water discharges and to reduce the discharge of pollutants from the storm water conveyance system to the “Maximum Extent Practicable.” For this evaluation, impacts to storm water quality would be considered significant if the Project did not attempt to address storm water pollution to the “maximum extent practicable.” The Lahontan RWQCB has adopted a Water Quality Control Plan for the South Lahontan Basin Area, which includes the Airport. The Water Quality Control Plan includes prohibitions, water quality standards, and policies for implementation of standards.
According to the 2002 Supplement, the existing drainage from the runways and taxiways begins with sheet flow from the pavement to the infield areas of the Airport and then infiltration into the ground. The drainage from the aircraft parking apron, access roads, and other paved areas begins as sheet flow to drainage inlet structures. The effluent is then piped to an infiltration trench located east of the current ground vehicle building where it infiltrates into the ground.
Stormwater Runoff
The 2002 Project involved 23,650 annual aircraft operations and various physical improvements to the Airport, including runway extension and widening, and a new 25,000-SF passenger terminal. Impervious surfaces increase the volume of stormwater runoff and could impact the relative quality of surface drainage. Runoff from impervious aeronautical surfaces may contain increased quantities of oils, grease, deicing fluid, and other complex hydrocarbon compounds.
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The 2002 Supplement concluded the aircraft operations and various physical improvements would have no significant environmental impacts on water quality or provide substantial additional sources of polluted runoff. There would be no violation of applicable water quality standards or water discharge requirements.
The Project proposes no new construction, pavement, or other ground-disturbing changes, thus, would result in no impacts to water quality associated with increases in impervious surfaces. The Project involves 17,482 annual aircraft operations, which would increase activities on the existing impervious aeronautical surfaces. Runoff from the existing pavement would drain into the surrounding ground, be carried through an oil/water separator, and ultimately discharged into leaching trenches or leaching fields, as under current conditions. Additionally, the storage and transfer of aviation fuels and fluids would create a potential for spill incidents, which could impact water quality. The existing fueling facilities are compliant with applicable regulations and compliance with the Airport’s SPCCP would be required. Comparatively, the current Project represents approximately 26 percent fewer aircraft operations than the project analyzed in the 2002 Supplement (23,650 annual aircraft operations). Project implementation would result in no greater long-term water quality impacts associated with stormwater runoff and accidental spills from aircraft operations than previously identified in the 2002 Supplement. Therefore, Project implementation would not violate any water quality standards or waste discharge requirements associated with stormwater runoff or accidental spills from aircraft operations.
Deicing Operations
The 2002 Project involved 23,650 annual aircraft operations, some requiring deicing during the winter. The 2002 Supplement concluded that all aircraft deicing operations would occur on the commercial airline apron and that the deicing fluid runoff from this area would be collected at an inlet and diverted to a holding tank for eventual disposal at an off-site location. Best Management Practices (BMP) would be used to mitigate potential water quality impacts. The 2002 Supplement concluded the aircraft deicing operations would have no significant environmental impacts on water quality or provide substantial additional sources of polluted runoff. There would be no violation of applicable water quality standards or water discharge requirements. The Project involves 17,482 annual aircraft operations by 2015. The number of aircraft requiring deicing would be approximately 18 per week.47 The existing on-site collection basin has sufficient holding capacity to store the spent deicing fluid until it can be collected and transported off site for disposal/recycling. Compliance with an approved Deicing Plan in accordance with FAA’s AC 150/5200-30A guidelines would be required. Comparatively, the current Project represents approximately 26 percent fewer aircraft operations than the project analyzed in the 2002 Supplement. Project implementation would result in no greater long-term water quality impacts associated with aircraft deicing operations than previously identified in the 2002 Supplement. Therefore, Project implementation would not violate any water quality standards or waste discharge requirements associated with aircraft deicing operations.
It is noted the Project is subject to compliance with the Lahontan RWQCB Water Quality Control Plan, which contains prohibitions, water quality standards, and policy implementation standards, in order to control storm water on site and prevent pollutants from non-point sources from entering and degrading surface or ground waters. Additionally, the proposed Project is subject to compliance with Code Section 12.08.090.
Mitigation Measures: No mitigation measures are required.
47 2007 Draft EIS, Page 5-62.
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b) Substantially deplete groundwater supplies or interfere substantially with groundwater recharge such that there would be a net deficit in aquifer volume or a lowering of the local groundwater table level (e.g., the production rate of pre-existing nearby wells would drop to a level which would not support existing land uses or planned uses for which permits have been granted)?
Less Than Significant Impact. The 2002 Project involved 333,000 annual enplanements and 23,650 annual aircraft operations, as well as various physical improvements to the Airport, including runway extension and widening, and a new 25,000-SF passenger terminal. The 2002 Supplement concluded the maximum annual water demand for the terminal building facility would be 18 acre-feet per year, well below the 2,700 acre-feet per day available. The 2002 Project would have no significant environmental impacts on water supply and it would not substantially deplete groundwater resources or interfere with groundwater recharge such that there would be a net deficit in aquifer volume or a lowering of a local groundwater table level.
The current Project considers 67,168 annual enplanements, 17,482 annual aircraft operations, and involves remodeling the existing maintenance building for use as a passenger terminal. No new facilities would be constructed. The Project’s proposed commercial air service and passenger terminal would create a demand for water. Comparatively, the current Project represents approximately 80 percent fewer enplanements and approximately 26 percent fewer aircraft operations than the project analyzed in the 2002 Supplement. Project implementation would result in no greater impacts involving water supply or groundwater resources than previously identified in the 2002 Supplement and conditions have not changed. Therefore, Project implementation would not substantially deplete groundwater supplies or interfere substantially with groundwater recharge, and sufficient water supplies would be available to serve the Project.
Mitigation Measures: No mitigation measures are required. c) Substantially alter the existing drainage pattern of the site or area, including through the alteration of the course of a stream or river, in a manner, which would result in substantial erosion or siltation on- or off-site?
Less Than Significant Impact. The 2002 Project involved various physical improvements to the Airport, including runway extension and widening, a new 25,000-SF passenger terminal, and automobile parking facilities, as well as 200 acres of grading. Impervious surfaces could increase the volume of stormwater runoff or alter existing drainage patterns. The 2002 Supplement concluded the improvements would have no significant environmental impacts on hydrology or create or contribute runoff, which would exceed the capacity of existing or planned storm-water drainage systems, or provide substantial additional sources of polluted runoff. The Project would involve no construction or other activities that would involve grading, other land disturbance, or an increase in impervious surface area at the Airport. The Project’s construction activities would be confined to the existing maintenance building and existing fencing. The Airport does not discharge stormwater into waters of the U.S., since stormwater runoff infiltrates to the ground or evaporates. Stormwater runoff from the aircraft parking apron and aircraft storage hangars would continue to be collected in inlets and conveyed via underground drainpipes to the existing infiltration trench. Project implementation would result in no greater impacts to drainage patterns than previously identified in the 2002 Supplement. Therefore, the proposed improvements would not substantially alter the existing drainage pattern of the site or area in a manner, which would result in substantial erosion or siltation on- or off-site, or flooding on- or off-site. Additionally, the Project would be subject to compliance with Lahontan RWQCB
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provisions require that runoff from impervious and disturbed surfaces generated by a 20-year storm (one inch per hour intensity) be retained and percolated into the ground. In addition to RWQCB requirement, the Project is subject to compliance with Code Section 12.08.090, which specifies drainage standards regarding runoff calculations and design.
Mitigation Measures: No mitigation measures are required. d) Substantially alter the existing drainage pattern of the site or area, including through alteration of the course of a stream or river, or substantially increase the rate or amount of surface runoff in a manner, which would result in flooding on- or off-site?
Less Than Significant Impact. Refer to Response 4.8(c).
Mitigation Measures: No mitigation measures are required.
e) Create or contribute runoff water which would exceed the capacity of existing or planned stormwater drainage systems or provide substantial additional sources of polluted runoff?
Less Than Significant Impact. Refer to Responses 4.8(a) and 4.8(c).
Mitigation Measures: No mitigation measures are required. f) Otherwise substantially degrade water quality?
Less Than Significant Impact. Refer to Response 4.8(a).
Mitigation Measures: No mitigation measures are required. g) Place housing within a 100-year flood hazard area as mapped on a federal Flood Hazard Boundary or Flood Insurance Rate Map or other flood hazard delineation map?
No Impact. The Project involves improvements to an existing airport and no new housing. Exhibit III-17, Floodplains Map, of the 2002 Supplement, illustrates the Flood Insurance Rate Map, published by the Federal Emergency Management Agency (FEMA). As depicted in Exhibit III-17, no part of the Airport is located within a floodplain. Project implementation would not place housing or structures within a 100-year flood hazard area.
Mitigation Measures: No mitigation measures are required. h) Place within a 100-year flow hazard area structures, which would impede or redirect flood flows.
No Impact. Refer to Response 4.8(g).
Mitigation Measures: No mitigation measures are required. i) Expose people or structures to a significant risk of loss, injury or death involving flooding, including flooding as a result of the failure of a levee or dam?
No Impact. Refer to Response 4.8(g).
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Mitigation Measures: No mitigation measures are required. j) Inundation by seiche, tsunami or mudflow?
No Impact. A seiche is an oscillation of a body of water in an enclosed or semi-enclosed basin, such as a reservoir, harbor, lake, or storage tank. A tsunami is a great sea wave, commonly referred to as a tidal wave, produced by a significant undersea disturbance such as tectonic displacement of a sea floor associated with large, shallow earthquakes. Mudflows result from the downslope movement of soil and/or rock under the influence of gravity. The Airport property is relatively distant from the ocean, not in the vicinity of a reservoir, harbor, lake, or storage tank capable of creating a seiche, and is not positioned downslope from an area of potential mudflow. Therefore, no impact would occur in this regard.
Mitigation Measures: No mitigation measures are required.
4.9 LAND USE AND PLANNING. Would the Project: a) Physically divide an established community?
No Impact. The Project’s construction activities would be confined to the existing maintenance building and existing fencing, which are located within the existing the Airport boundaries. The proposed Project would not physically divide an established community.
Mitigation Measures: No mitigation measures are required. b) Conflict with applicable land use plan, policy or regulation of an agency with jurisdiction over the project (including but not limited to the general plan, specific plan, coastal program, or zoning ordinance) adopted for the purpose of avoiding or mitigating an environmental effect?
Less Than Significant Impact.
Town of Mammoth Lakes General Plan 2007
Mammoth Yosemite Airport’s land use designation is Airport (A).48 This designation allows aviation, fueling, and fixed-base operator services at the Airport. The Project involves the proposal by Horizon Air to initiate scheduled commercial air service into the Airport. The Project also involves remodeling the existing maintenance building at the Airport for use as a passenger terminal. The proposed commercial air service and terminal are allowed uses/activities within the Airport (P) designation. Therefore, the proposed Project is considered consistent with the intended use for the property, according to the 2007 General Plan.
The following are key 2007 General Plan (Economy Element) policies that are relevant to the proposed Project:
48 The distribution of land use designations throughout the Town is illustrated in Figure 5, Land Use Diagram, of the General Plan 2007. The Airport (A) designation is not identified in Figure 5, because it is not located on the area shown. However, the land area on which the Airport and its immediate surroundings is located was annexed into the Town in April 1995.
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E.1.E. Policy: Re-establish year-round scheduled air service and continue charter air serve at Mammoth Yosemite Airport.
E.1.F. Policy: Establish and maintain air service connecting the Mammoth Lakes area with destination visitor markets.
E.1.F.2. Action: Upgrade the Mammoth Yosemite Airport terminal to allow for regional air service.
E.1.G. Policy: Develop facilities that support commercial and charter air carrier service.
The proposed Project would be in compliance with these 2007 General Plan policies in that it involves the proposal by Horizon Air to initiate scheduled commercial air service into the Airport. Additionally, the Project proposes the renovation of a maintenance hangar into a passenger terminal, which would be in support of the proposed scheduled commercial air service and directly implements Action E.1.F.2.
Town of Mammoth Lakes Municipal Code
Title 17 of the Municipal Code, Zoning, establishes classifications of zones and regulations within these zones. According to the Town’s official Zoning Map, the Airport property is zoned Airport (A-)Zone. Code Chapter 17.28, Special Purpose Zones, establishes special purpose zones, because of the special or unique land use characteristics with which they are associated and because of the need to implement specific sections of the General Plan. The Airport is located in the Airport Zone (A) (Chapter 17.28 - Article X). Additionally, Code Chapter 18.02, Mammoth Lakes Airport Rules and Regulations, provides the rules and regulations “to protect the health, safety, and peace and to promote the welfare and convenience of the general public using the Mammoth Lakes Airport or affected by activities related to the Airport by providing for the orderly conduct of activities on or related to the Airport.
The proposed Project is analyzed below for consistency with Chapter 17.28 - Article X and Chapter 18.02.
CHAPTER 17.28 - ARTICLE X
Code Section 17.28.600, Purposes
The purpose of the (A) Airport Zone is “to implement the Mammoth Lakes Airport Layout Plan, and the goals and policies in the Mammoth Lakes General Plan related to airport facilities.” The Project proposes remodeling the existing maintenance building at the Airport for use as a 5,000-square foot (SF) passenger terminal and reinitiation of regularly scheduled commercial air service into the Airport. The terminal would be consistent with the Airport layout plan. Additionally, the proposed terminal and air service would be in compliance with the 2007 General Plan policies, as concluded above.
Code Section 17.28.610, Permitted and Conditional Uses
The Project involves remodeling the existing maintenance building at the Airport for use as a passenger terminal. Terminals are categorized as “airports, terminals, hangers, and other airport facilities and uses subject to all applicable regulations of the Federal Aviation
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Administration and the Mammoth Lakes Airport. Terminal facilities are permitted in the A Zone subject to the Mammoth Lakes Airport Layout Plan. The Project also involves reinitiation of regularly scheduled commercial air service into the Airport. Aircraft are categorized as “aircraft subject to rules and regulations of the Mammoth Lakes Airport. Aircraft are permitted in the A Zone subject to the Mammoth Lakes Airport Layout Plan.
Code Section 17.28.620, Development Standards
The development standards that apply to all land and structures in the A Zone are contained in Code Section 17.28.620. Through the Project application process (i.e., Mammoth Lakes Airport Layout Plan), the proposed terminal improvements would be further reviewed by the Town to confirm consistency with the Section 17.28.620 standards, the Zoning Ordinance, and other relevant regulatory documents. With the Town’s discretionary review of the proposed terminal through the established procedures, Project implementation would not conflict with Code Section 17.28.620 and a less than significant impact would occur in this regard. Code Chapter 18.02, Mammoth Lakes Airport Rules and Regulations
The rules and regulations that apply to all activities related to the Airport are contained in Code Chapter 18.02. Through the Project application process (i.e., Mammoth Lakes Airport Layout Plan), the proposed scheduled commercial air service would be further reviewed by the Town to confirm consistency with the Chapter 18.02 rules and regulations, the Zoning Ordinance, and other relevant regulatory documents. With the Town’s discretionary review of the proposed air service, Project implementation would not conflict with Code Chapter 18.02 and a less than significant impact would occur in this regard.
Overall, with the Town’s discretionary review of the proposed Project, Project implementation would not conflict with the Zoning Ordinance and a less than significant impact would occur in this regard.
Airport Land Use Policy Plan for the Mammoth/June Lake Airport (May 1986)
The 1986 Mammoth/June Lake Airport Land Use Plan (ALUP) establishes a comprehensive land use plan that defines the type and pattern of future development in the 28 square mile area surrounding the existing Airport. The ALUP creates an Airport Development District (ADD) within which future development may occur. The ALUP primarily provides a framework for the orderly growth and development of the Airport over the next 20 years. The ALUP involved major development and expansion of the Airport terminal area, including additional aircraft support facilities, a new passenger terminal, an airport hotel, and extensive infrastructure improvements. Landside improvements are limited to remodeling an existing maintenance building. As concluded in Response 4.7(e), the Project would be in compliance with the ALUP regarding the Airport Safety Zone, Airport Overflight and Traffic Pattern Zone, and Airport Height Restrictions Zone, since no new structures, objects, or obstructions are proposed. Additionally, the Project involves 67,168 annual enplanements and 17,482 annual aircraft operations, which represent approximately 78 percent fewer enplanements and 42 percent fewer aircraft operations than the project analyzed in the 1986 EIR/EA for the ALUP (310,000 annual enplanements and 30,000 annual aircraft operations). Project implementation would result in no greater impacts involving consistency with the ALUP than previously identified in the 1986 EIR/EA. Therefore, the proposed Project would not conflict with the applicable policies of the ALUP and a less than significant impact would occur in this regard.
Mitigation Measures: No mitigation measures are required.
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c) Conflict with any applicable habitat conservation plan or natural community conservation plan?
No Impact. Refer to Response 4.4(f).
Mitigation Measures: No mitigation measures are required.
4.10 MINERAL RESOURCES.
The findings of the 1986 EIR/EA (Pages 62 to 65) are summarized as follows:
The airport planning area is situated within the Mono-Long Valley Known Geothermal Resource Area (KGRA), which extends from Long Valley to Mono Lake.
Engineering and environmental studies are currently in progress for the development of at least one 10 megawatt power generation plant within the lease area.
There are two existing sand and gravel pits within the area: the privately owned Sierra Quarry site, southwest of the airport and the Forest Service site 1,200 feet north of the airport terminal area.
The Draft EIR identified the following impacts for the proposed geothermal development project, which are directly related to the Airport Land Use Plan:
1. Vapor emissions from power plant cooling towers could cause visible plumes, which might affect airport operations.
The proposed expanded terminal facilities, . . . . . are essentially incompatible with the gravel pit operation.
Conflicts with proposed airport development should be anticipated, however, leading to the eventual closure of the site (Forest Service sand and gravel pit). The following mitigation measures should be included in use permit conditions for the project:
1. Vapor emissions and/or steam plumes shall not interfere with aircraft operations in the vicinity of the airport. 2. All building structures, towers, transmission lines, and other above-ground structures shall comply with the height restrictions of the Airport Land Use Policy Plan. 3. Lighting systems for power plant facilities shall be designed to be low-level and shielded to avoid interferences with night airport operations.
Would the Project: a) Result in the loss of availability of a known mineral resource that would be of value to the region and the residents of the state?
Less Than Significant Impact. The 1986 Project involved major development and expansion of the Airport terminal area, including additional aircraft support facilities, a new passenger
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terminal, an airport hotel, and extensive infrastructure improvements. The 1986 EIR/EA concluded that with implementation of recommended mitigation measures, impacts would be less than significant in this regard. Additionally, the current Project represents approximately 42 percent fewer aircraft operations than the project analyzed in the 1986 EIR/EA (30,000 annual aircraft operations by 1995). Project implementation would result in no greater impacts to mineral resources than previously identified in the 2002 Supplement and conditions have not changed. Therefore, Project implementation would result in a less than significant impact regarding the loss of availability of a known mineral resource.
Mitigation Measures: No mitigation measures are required. b) Result in the loss of availability of a locally-important mineral resource recovery site delineated on a local general plan, specific plan or other land use plan?
Less Than Significant Impact. Refer to Response 4.10(a).
Mitigation Measures: No mitigation measures are required.
4.11 NOISE.
The findings of the 2002 Supplement (Pages III-86 to III-94), are summarized as follows:
The area exposed to aircraft noise of 65 dBA CNEL and higher for the proposed project remains within the airfield boundary of the Airport on either Airport property or vacant land controlled by the Airport through leases or permits. There are no sensitive land uses and no people living within the 65 dBA CNEL noise exposure area. The 60 dBA CNEL and higher noise exposure area remains largely on Airport property, vacant land, or the U.S. Highway 395 right of way. Current land use plans show this area as remaining as compatible land uses.
There are no populated areas or other incompatible land uses planned within the 65 dBA CNEL or higher noise exposure areas for the proposed project for 2003 or 2022.
The proposed project would not result in the exposure of persons to or generation of noise levels in excess of 60 dBA CNEL or indoor noise level greater than 45 dBA CNEL in areas or on facilities not compatible with that noise level. Therefore, the proposed plan does not significantly impact the environment in terms of operational noise.
The findings of the 2007 Draft EIS are summarized as follows:
There are no noise-sensitive land uses within the CNEL 65 dBA contour in either the 2009 or 2015 Proposed Action. Compared to the respective No-Action Alternative, less than one additional acre would be exposed to CNL 65 dBA or higher noise levels. There would be no housing units or people residing within the CNEL 65 dBA contour. The Proposed Action would not cause noise-sensitive areas to experience an increase in noise of CNEL 1.5 dBA or more at or above CNEL 65 dBA, when compared to the No- Action Alternative. Therefore, the Proposed Action would not cause a significant noise impact.
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Would the Project result in: a) Exposure of persons to or generation of noise levels in excess of standards established in the local general plan or noise ordinance, or applicable standards of other agencies?
Less Than Significant Impact. It is difficult to specify noise levels that are generally acceptable to everyone; what is annoying to one person may be unnoticed by another. Standards may be based on documented complaints in response to documented noise levels, or based on studies of the ability of people to sleep, talk or work under various noise conditions. All such studies; however, recognize that individual responses vary considerably. Standards usually address the needs of most of the general population.
Title 8.0, Health and Safety, of the Code covers all noise standards. Also, Code Chapter 8.16, Noise Regulation, sets forth all noise regulations controlling unnecessary, excessive and annoying noise and vibration in the Town. As outlined in Code Chapter 8.16, maximum exterior noise levels are based on land use districts. In addition to interior and exterior noise standards, the Town provides regulations for construction activities and other types of noises in Code Section 8.16.090, Prohibited Acts.
Short-Term Noise Impacts
Short-term noise impacts would result from construction activities associated with extension of the runway and remodeling of the existing maintenance/operations building for use as a passenger terminal. The proposed passenger terminal would contain Transportation Security Administration (TSA) facilities and would be remodeled to comply with TSA requirements.
There are no sensitive noise receptors in the immediate vicinity of the Project site. Additionally, the majority of construction activities would occur within the maintenance/operations building as it is remodeled to be used as a passenger terminal. Construction activities within the maintenance/operations building would not require heavy-duty equipment that would produce excessive noise or ground borne noise and vibration capable of impacting sensitive receptors. Additionally, any construction-related noise would be temporary in nature and would cease upon completion of the construction phase. Short-term noise impacts would be less than significant, as there are no sensitive receptors immediately surrounding the Project site or within the vicinity of the maintenance/operations building.
Long-Term Noise Impacts
Aircraft Noise
The Federal Aviation Administration (FAA) sets noise limits for commercial aircraft (14 CFR Part 36) and establishes procedures for airport noise studies and land use compatibility evaluations (14 CFR Part 150) in the Federal Aviation Regulations. According to the Town of Mammoth Lakes General Plan Update EIR (May 2007), the Airport currently has 400 flights per month, primarily by single-engine private aircraft. A commercial turbo-prop provides limited service. Existing Airport noise does not contribute substantially to the noise level in the Town.
As required by the California Airport Noise Regulation (CCR Title 21, Subchapter 6), aircraft noise exposure has been quantified using the Community Noise Equivalent Level (CNEL). Paragraph 85.a of FAA Order 5050.4A specifies the use of the FAA's average day-night noise level metric (DNL) when performing noise exposure analyses in order to be consistent with
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those used for environmental impact statements and environmental assessments as well as in FAA Part 150 Noise Compatibility Programs. However, in the State of California, the FAA accepts the CNEL metric as a substitute for the DNL metric. Noise exposure criterion levels of 60, 65, 70, and 75 CNEL were selected, as required by the California Department of Transportation, Division of Aeronautics.
There are no residential land uses or noise sensitive sites within the CNEL 65 dBA contour. Table N-1, Existing Impacts to Land Use, identifies land use and acreage within the CNEL 65 dB contours for 2005 Existing Conditions.
Table N-1 Existing Impacts to Land Use
Noise Contour Interval (CNEL) Land Use 65 dBA 70 dBA 75 dBA Total Off-Airport Public/Quasi-Public Facilities 1.2 0.0 0.0 1.2 Resource Management 1.3 0.0 0.0 1.3 Right of Way 0.8 0.0 0.0 0.8 Off-Airport Land Use Total 3.4 0.0 0.0 3.4 On-Airport Public/Quasi-Public Facilities 57.1 36.7 29.4 123.2 On-Airport Land Use Total 57.1 36.7 29.4 123.2 GRAND TOTAL 60.5 36.7 29.4 126.5 Notes: 1. Numbers may not add, due to rounding. 2. All units are in acres. Source: U.S. Department of Transportation Federal Aviation Administration, Draft Environmental Impact Statement Request For Operations Specifications Amendment By Horizon Air to Provide Scheduled Air Service to Mammoth Yosemite Airport, November 2007.
In 2009, with implementation of the proposed Project, there would be 13,801 general aviation operations with an additional 448 Q400 Dash 8 aircraft operations during the winter season for a total of 14,249 annual operations. In total, it is an average of approximately 39.0 daily operations. The fleet mix and day/evening/night split would not change from existing conditions.
Under 2015 proposed Project conditions, there would be 15,451 general aviation operations with an additional 2,032 Q400 Dash 8 aircraft operations from the summer and winter seasons combined (eight winter ski season flights per day and two summer season flights per day have been forecasted). In total, it is an average of approximately 47.9 daily operations. As with the 2009 forecast, the fleet mix and day/evening/night split would not change from existing conditions.
Table N-2, Proposed Project Impacts to Land Use, identifies land use and acreage within the CNEL 65 dBA contours for 2009 and 2015 conditions of the proposed Project. There are no noise-sensitive land uses within the CNEL 65 dBA contour in either the 2009 or 2015 proposed Project condition. Project implementation would result in no greater noise impacts associated with aircraft operations than previously identified in the 2002 Supplement and conditions have not changed. Comparatively, the current Project represents approximately 80 percent fewer enplanements and approximately 26 percent fewer aircraft operations than the project analyzed in the 2002 Supplement. Impacts would be less than significant.
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Table N-2 Proposed Project Impacts to Land Use
Noise Contour Interval (CNEL)1 Land Use 2009 Impacts to Land Use2 2015 Impacts to Land Use2 65 dBA 70 dBA 75 dBA Total 65 dBA 70 dBA 75 dBA Total Off-Airport Public/Quasi-Public Facilities 1.6 0.0 0.0 1.6 3.0 0.0 0.0 3.0 Resource Management 1.7 0.0 0.0 1.7 2.9 0.0 0.0 2.9 Right of Way 1.2 0.0 0.0 1.2 2.6 0.0 0.0 2.6 Off-Airport Land Use Total 4.5 0.0 0.0 4.5 8.5 0.0 0.0 8.5 On-Airport Public/Quasi-Public Facilities 57.6 37.7 30.6 125.9 58.7 40.4 34.0 133.1 On-Airport Land Use Total 57.6 37.7 30.6 125.9 58.7 40.4 34.0 133.1 GRAND TOTAL 62.1 37.7 30.6 130.4 67.1 40.4 34.0 141.6 Notes: 1. Numbers may not add, due to rounding. 2. All units are in acres. Source: U.S. Department of Transportation Federal Aviation Administration, Draft Environmental Impact Statement Request For Operations Specifications Amendment By Horizon Air to Provide Scheduled Air Service to Mammoth Yosemite Airport, November 2007.
Mobile Noise Sources
The existing and future roadway noise levels in the vicinity of the Project site were modeled using the Federal Highway Administration’s Highway Noise Prediction Model (FHWA-RD-77- 108) together with several roadway and site parameters. Noise projections are based on modeled vehicular traffic as derived from the Mammoth Lakes-Yosemite Valley Airport Traffic Impact Analysis (Traffic Impact Analysis) prepared by LSA Associates (February 5, 2008). A 60 mile per hour average vehicle speed was assumed for vehicles traveling along U.S. 395 and a 30 to 40 mile per hour average vehicle speed was assumed for the other roadways. Refer to Appendix 9.2, Noise Data, for traffic noise model sheets. Average daily traffic estimates were obtained from the Traffic Impact Analysis. Existing modeled traffic noise levels are shown on Table N-3, Existing Traffic Noise Levels.
Project implementation would result in additional traffic on adjacent roadways, thereby increasing vehicular generated noise in the Project vicinity. Traffic volumes were analyzed under “Year 2025 Baseline” and “Year 2025 With Airport” scenarios and compared; refer to Table N-4, Future Traffic Noise Scenarios. As indicated in Table N-4, under the “Year 2025 Baseline” scenario, noise levels at 100 feet from the centerline would range from 46.8 dBA to 62.5 dBA. The highest noise levels would occur along U.S. Highway 395 Northbound (north and south of Hot Creek Fish Hatchery Road).
During the “Year 2025 With Airport” scenario, traffic noise levels would range from 50.0 dBA to 62.8 dBA. Similar to the “Year 2025 Baseline” scenario, the highest noise levels would occur along U.S. Highway 395 Northbound (north of Hot Creek Fish Hatchery Road). Table N-4 also compares the “2025 Baseline” scenario with the “2025 With Airport Scenario”. As indicated in Table N-4, the greatest noise increase would be 3.3 dBA and would occur along Hot Creek Fish
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Hatchery Road (west of U.S. 395 Northbound). This is considered a less than significant impact.
Table N-3 Existing Traffic Noise Levels
Existing dBA @ 100 Distance from Roadway Centerline to: (Feet) Roadway Segment Feet from ADT 60 CNEL 65 CNEL 70 CNEL Roadway Noise Noise Noise Centerline Contour Contour Contour Hot Creek Fish Hatchery Road West of U.S. 395 Southbound N/A N/A N/A N/A N/A Between U.S. 395 Southbound and U.S. 395 200 44.5 10 5 2 Northbound West of U.S. 395 Northbound 420 47.8 17 8 4 U.S. 395 Southbound North of Hot Creek Fish Hatchery Road 4,550 60.0 135 63 29 South of Hot Creek Fish Hatchery Road 4,450 59.9 133 62 29 U.S. 395 Northbound North of Hot Creek Fish Hatchery Road 6,750 61.7 176 82 38 South of Hot Creek Fish Hatchery Road 6,670 61.7 175 81 38 Notes: N/A = Not Applicable; there would not be any traffic volumes along Hot Creek Fish Hatchery Road during the 2025 Baseline scenario; ADT = average daily trips; dBA = A-weighted decibels; CNEL = community noise equivalent level Source: Based on traffic data prepared by LSA Associates, Mammoth Lakes-Yosemite Valley Airport Traffic Impact Analysis, February 5, 2008.
Table N-4 Future Traffic Noise Scenarios
2025 Baseline 2025 With Airport Difference in dBA @ dBA @ 100 dBA @ 100 Significant Roadway Segment Feet from Feet from 100 Feet ADT ADT Impact? Roadway Roadway from Centerline Centerline Roadway Hot Creek Fish Hatchery Road West of U.S. 395 Southbound N/A N/A N/A N/A N/A N/A Between U.S. 395 Southbound and U.S. 395 340 46.8 700 50.0 3.2 No Northbound West of U.S. 395 Northbound 360 47.1 770 50.4 3.3 No U.S. 395 Southbound North of Hot Creek Fish Hatchery Road 5,440 60.8 5,970 61.2 0.4 No South of Hot Creek Fish Hatchery Road 5,370 60.7 5,370 60.7 0 No U.S. 395 Northbound North of Hot Creek Fish Hatchery Road 8,130 62.5 8,630 62.8 0.3 No South of Hot Creek Fish Hatchery Road 8,040 62.5 8,060 62.5 0 No Notes: N/A = Not Applicable; there would not be any traffic volumes along Hot Creek Fish Hatchery Road during the 2025 Baseline scenario; ADT = average daily trips; dBA = A-weighted decibels; CNEL = community noise equivalent level Source: Based on traffic data prepared by LSA Associates, Mammoth Lakes-Yosemite Valley Airport Traffic Impact Analysis, February 5, 2008.
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Impact Conclusion
Short-term noise impacts would be less than significant, as there are no sensitive receptors immediately surrounding the Project site or within the vicinity of the maintenance/operations building. Long-term impacts would be less than significant since there are no noise-sensitive land uses within the 65 CNEL contour in either the 2009 or 2015 proposed Project condition. Compared to the respective no Project conditions, less than one additional acre would be exposed to 65 CNEL or higher noise levels. Although Project implementation would result in additional traffic on adjacent roadways, the greatest noise increase would be considered a less than significant impact.
The 2002 Supplement found that the proposed Project would not result in the exposure of persons to or generation of noise levels in excess of 60 CNEL or indoor noise level greater than 45 CNEL in areas or on facilities not compatible with that noise level. The proposed Project involves 67,168 annual enplanements and 17,482 annual aircraft operations, and involves remodeling the existing maintenance building for use as a passenger terminal. No new facilities would be constructed. Comparatively, the current Project represents approximately 80 percent fewer enplanements and approximately 26 percent fewer aircraft operations than the project analyzed in the 2002 Supplement. Project implementation would result in no greater noise impacts than previously identified in the 2002 Supplement. As a result, the proposed Project would not generate of noise levels in excess of City, County, and/or federal standards. Impacts would be less than significant.
Mitigation Measures: No mitigation measures are required. b) Exposure of persons to or generation of excessive groundborne vibration or groundborne noise levels?
Less Than Significant Impact. Airplane takeoffs would create groundborne vibration. According to the Town of Mammoth Lakes 2007 General Plan EIR residences and schools are required to be located outside of the Airport’s 65 dBA CNEL noise contour. The 65 CNEL noise contour would be located within the Airport boundaries and would not extend beyond the runway. Additionally, there are no sensitive receptors or structures in the immediate vicinity of the Airport.
The current Project represents approximately 80 percent fewer enplanements and approximately 26 percent fewer aircraft operations than the project analyzed in the 2002 Supplement. Project implementation would result in no greater noise impacts than previously identified in the 2002 Supplement. As a result, groundborne vibration impacts would be less than significant.
Mitigation Measures: No mitigation measures are required. c) A substantial permanent increase in ambient noise levels in the project vicinity above levels existing without the project?
Less Than Significant Impact. The proposed Project would not cause noise-sensitive areas to experience an increase in noise of 1.5 dBA or more at or above 65 CNEL, when compared to no Project conditions in either 2009 or 2015. Additionally, the 65 CNEL noise contour would not extend beyond the Airport runway or the Project site. The current Project represents approximately 80 percent fewer enplanements and approximately 26 percent fewer aircraft
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operations than the project analyzed in the 2002 Supplement. Project implementation would result in no greater noise impacts than previously identified in the 2002 Supplement. Therefore, the proposed Project would not cause a substantial permanent increase in ambient noise levels. Also, refer to Response 4.11(a).
Mitigation Measures: No mitigation measures are required. d) A substantial temporary or periodic increase in ambient noise levels in the project vicinity above levels existing without the project?
Less Than Significant Impact. Construction-related activities and equipment used during the Project’s construction phase would not result in a temporary or periodic increase in ambient noise levels above existing levels since the majority of construction activities would occur within the maintenance/operations building. Construction activities would result in less than significant short-term noise impacts since there are no sensitive receptors in the immediate vicinity. Refer to Response 4.11(a) and 4.11(c).
Noise typically associated with the operation activities of the Airport facility would occur from the inbound and outbound flights. There are no noise-sensitive land uses within the 65 CNEL contour in either the 2009 or 2015 proposed Project conditions. Additionally, the proposed Project would not cause noise-sensitive areas to experience an increase in noise of 1.5 dBA or more at or above 65 CNEL, when compared to no Project conditions. The current Project represents approximately 80 percent fewer enplanements and approximately 26 percent fewer aircraft operations than the project analyzed in the 2002 Supplement. Project implementation would result in no greater noise impacts than previously identified in the 2002 Supplement. Therefore, the proposed Project would not cause a significant noise impact. Impacts would be less than significant. Also, refer to Response 4.11(a).
Mitigation Measures: No mitigation measures are required. e) For a project located within an airport land use plan or, where such a plan has not been adopted, within two miles of a public airport or public use airport, would the project expose people residing or working in the project area to excessive nose levels?
Less Than Significant Impact. The Mammoth Yosemite Airport is within the 1986 Airport Land Use Policy Plan for the Mammoth/June Lake Airport (ALUP). The ALUP establishes a comprehensive land use plan that defines the type and pattern of future development in the 28 square mile area surrounding the existing Airport. The ALUP involved development and expansion of the Airport terminal area, including additional aircraft support facilities, a new passenger terminal. As such, the proposed Project is planned within the ALUP. Additionally, the proposed Project would not expose people to excessive noise levels since the 65 CNEL noise contour would not extend beyond the Airport runway.
The proposed Project involves 67,168 annual enplanements and 17,482 annual aircraft operations, and involves remodeling the existing maintenance building for use as a passenger terminal. No new facilities would be constructed. The Project proposes 78 percent fewer enplanements and 42 percent fewer aircraft operations than the project analyzed in the 1986 EIR/EA for the ALUP. It is further noted that the Project site is within the Airport Development District (ADD) and would be reviewed by the Mono County Airport Land Use Commission (ALUC) to ensure consistency with the ALUP. Project implementation would result in no greater
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noise impacts than previously identified in the 1986 ALUP EIR/EA or the 2002 Supplement. Therefore, a less than significant impact would occur. Also, refer to Response 4.9(b).
Mitigation Measures: No mitigation measures are required. f) For a project within the vicinity of a private airstrip, would the project expose people residing or working in the project area to excessive noise levels?
Less Than Significant Impact. Refer to Response 4.11(e).
Mitigation Measures: No mitigation measures are required.
4.12 POPULATION AND HOUSING.
The findings of the 1986 EIR/EA (Pages 84 to 85) are summarized as follows:
Ultimate projected populations associated with implementation of the ALUP are considered to represent moderate growth. . . . . Maximum daily populations are expected to reach 1,500 PAOT during peak recreational periods.
The Airport Land Use Plan is itself a general mitigation measure for the impacts associated with future land uses and population growth in the airport planning area.
The findings of the 2002 Supplement (Table 1, #11, Population and Housing, and Section 5.3, Growth Inducing Impact of the Project) are summarized as follows:
Increased Employment at airport.
New employees may increase the demand for affordable housing in the Town of Mammoth Lakes.
The growth in tourism of the Mammoth Lakes region is a fact recognized in the Town of Mammoth Lakes General Plan/Mono County General Plan [5-1]. Development is continuing in the Town of Mammoth Lakes with construction beginning on 2,403 new tourist units and 134,000 sq. ft. of new commercial development as well as just completed a new 18-hole golf course. In addition, plans are underway for a $131 million upgrade and renovation to mountain lifts, trails, equipment, and facilities. Other developments, including the Dempsey Corporation’s Snowcreek development, also have real estate plans, which add more rooms. Within the next 10 years, it is anticipated that approximately 6,000 units will be developed to accommodate the projected growth in tourism. The growth projections are based upon the Town’s marketing program, not development of local air service.
Would the Project: a) Induce substantial population growth in an area, either directly (for example, by proposing new homes and businesses) or indirectly (for example, through extension of roads or other infrastructure)?
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Less Than Significant Impact. The 1986 Project involved major development and expansion of the Airport terminal area, including additional aircraft support facilities, a new passenger terminal, an airport hotel, and extensive infrastructure improvements, as well as a planned unit development. The 1986 EIR/EA concluded the ALUP is itself a general mitigation measure for the impacts associated with future land uses and population growth in the Airport planning area.
The proposed Project would not induce direct population growth in the area, since it does not involve the development of residential or commercial uses. Further, the Project would not induce indirect population growth through the extension of roads or other infrastructure into an outlying area. As tourism continues to grow, it is anticipated that more passengers would use the air carrier service at the Airport. Therefore, more employment opportunities would also be generated by the Airport and airlines. At the same time, the increase in tourism would stimulate secondary growth in services offered by the community, such as additional hotels and restaurants, through which more job opportunities would be created. As a result, more people could eventually move to the Mammoth Lakes area. New housing would have to be built to accommodate the increase in workers in the area. Other than the direct and indirect jobs related to employment at the Airport, the increase in population and housing and expansion of the region’s economy would be expected to occur with or without the improvement of the Airport. The 2007 General Plan assumes buildout in Year 2024 of 16,710 housing units and 60,700 peak people at one time (PAOT). The potential growth is for 6,839 housing units and 26,436 PAOT. As the PAOT is determined by the 2007 General Plan, which assumes commercial service at the Airport, the Project itself would not be directly growth inducing or exceed the PAOT assumptions.
The Project does not involve any new airside or landside improvements, rather is limited to remodeling an existing maintenance building. The Project proposes to initiate scheduled commercial air service into the Airport (67,168 annual enplanements and 17,482 annual aircraft operations), which would increase the peak maximum daily population of people at one time. However, the maximum population is “capped” by the General Plan Land Use Element and arrival to the area through commercial air service rather than by ground transportation would not change the maximum population. It may however, accelerate the rate of growth. Comparatively, the Project’s scheduled commercial air service represents approximately 78 percent fewer enplanements and 42 percent fewer aircraft operations than the project analyzed in the 1986 EIR/EA for the ALUP (310,000 annual enplanements and 30,000 annual aircraft operations). As concluded in Response 4.9(b), the Project would be in compliance with the ALUP. Project implementation would result in no greater impacts involving population growth than previously identified in the 1986 EIR/EA. Therefore, the annual aircraft operations associated with the proposed Project would result in less than significant impacts regarding population growth in the area.
The 2002 Supplement concluded that new employees could increase the demand for affordable housing in the Town. Potential impacts associated with the demand for affordable housing were concluded as less than significant following compliance with the Town’s Code requirements. Similarly, the employment generated by the proposed Project could create a demand for affordable housing in the Town. Compliance with Town Code Chapter 17.36.040, Housing Mitigation Development Plan, would reduce impacts to less than significant levels.
Mitigation Measures: No mitigation measures are required.
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b) Displace substantial numbers of existing housing, necessitating the construction of replacement housing elsewhere?
No Impact. The Project’s construction activities would be confined to the existing maintenance building and existing fencing. No housing exists on the Airport property. Additionally, no new facilities would be constructed as part of the proposed Project. Therefore, Project implementation would not displace any existing housing or people.
Mitigation Measures: No mitigation measures are required. c) Displace substantial numbers of people, necessitating the construction of replacement housing elsewhere?
No Impact. Refer to Response 4.12(b).
Mitigation Measures: No mitigation measures are required.
4.13 PUBLIC SERVICES.
The findings of the 2002 Supplement (Pages III-95 to III-98) are summarized as follows:
Public Services include fire protection, police protection, schools, snow removal/roadway maintenance, neighborhood and regional parks, and libraries. a) Would the project result in substantial adverse physical impacts associated with the provision of new or physically altered governmental facilities, need for new or physically altered governmental facilities, the construction of which could cause significant environmental impacts, in order to maintain acceptable service ratios, response times or other performance objectives for any of the public services:
1) Fire protection?
Less Than Significant Impact. The 1986 EIR/EA concluded existing emergency assistance and fire protection facilities at the Airport were inadequate and required extensive upgrades. Since 1986, upgrades to the Airport’s emergency assistance and fire protection facilities have been implemented. More specifically, the Airport Emergency Plan (approved by the FAA on September 26, 2005) consists of two plans: the Town’s Emergency Operations Plan (EOP) for major incidents; and the Airport Emergency Plan (AEP). The Town’s EOP covers the mitigation, preparedness, response and recovery from major incidents or natural disasters. Details regarding resources, command and control, and contacts are addressed. During an incident at the Airport, if Airport resources are insufficient, the Airport would contact the County dispatch center for emergency services. The AEP ensures the safety and service for people and the community. Under the AEP, the Airport has authority to administer the Airport Rules and Regulations, and has provided an Airport Manager/Staff to ensure the safe and efficient operation of the Airport. The AEP’s area of control is incidents occurring on the Airport. The first response to an emergency at the Airport would be the Aircraft Rescue and Fire Fighting (ARFF) vehicle. The AEP further details: the Action Plan; Alert, Warning and Public Information, Communications; Resources; Situations Requiring Outside Resources; Airport Special Conditions; Incident Investigatory and Recovery Phase; and Training. The Project
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involves 17,482 annual aircraft operations, which would generate a demand for emergency and fire protection services and facilities.
The Airport is located in the Long Valley Fire Protection District (LVFPD), one of 11 local volunteer fire protection districts that provide fire protection throughout Mono County; refer to Response 4.7(h). The LVFPD, which is located at 3605 Crowley Lake Drive in Crowley Lake, employs 31 paid per call firefighters and six non-firefighting staff.
The Insurance Service Office (ISO) uses a credit rating system to determine fire insurance rates in different areas. The grading system compares the fire protection that is needed in an area with the fire protection that is locally available. A rating of “1” represents the highest level of fire protection, the lowest fire hazard and generally lower rates. A rating of “10” indicates the lowest level of fire protection. The Long Valley District has an ISO Rating of 9.
The Mono County Fire/Rescue Department provides emergency service to the Airport. The Department is responsible by ordinance for all emergency medical calls and ambulance inter- facility transfers received within the County. The Department employs 23 paramedic/firefighters and two emergency medical technicians (EMT)/firefighters. Additionally, four advanced life support (ALS) ambulances are staffed 24 hours a day, usually with two paramedics. One reserve ALS ambulance is fully equipped and is placed in service when needed.
With implementation of the 2007 General Plan, fire protection services were planned for expansion of the Airport. Continued implementation of the Airport’s AEP along with the existing services provided by the LVFPD and Mono County Fire/Rescue Department would ensure that Project implementation would not result in substantial adverse physical impacts associated with fire protection services.
Mitigation Measures: No mitigation measures are required.
2) Police protection?
Less Than Significant Impact. The 1986 EIR/EA concluded existing emergency assistance at the Airport were inadequate and required extensive upgrades. Since 1986, upgrades to the Airport’s emergency assistance facilities have been implemented. According to the Town of Mammoth Lakes 2007 General Plan EIR, police protection and law enforcement in the Town are provided by the Mammoth Lakes Police Department (MLPD), the Mono County Sheriff’s Department (MCSD), and the California Highway Patrol (CHP). The MLPD provides all non- traffic related services for the areas within the Town’s incorporated boundary, including the Airport. Criminal investigation calls, the primary job function of the MLPD, increase during the peak visitor months. MLPD is responsible for all traffic related offences within the Town except for along State Route 203 where the CHP also provides traffic related services. The CHP and MCSD are primarily responsible for all other law enforcement issues in the Town of Mammoth Lakes Planning Area located outside of the Municipal Boundary.
The MLPD staff is currently comprised of 20 sworn officers, two non-sworn investigators and one Animal Control officer, all of whom operate out of a leased facility located along Old Mammoth Road.49 The facility, which consists of approximately 3,000 square feet of administrative offices and a booking area, is considered undersized and inadequate for the department. However, plans are currently underway for a replacement facility. The MLPD
49 Ibid.
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currently owns six marked and four unmarked patrol cars. Typically, two to four sworn officers are on duty at any one time. Dispatches for both the MLPD and MCSD are routed by Mono County.
With implementation of the 2007 General Plan, police protection services were planned for expansion of the Airport. Continued implementation of the Airport’s AEP along with the existing services provided by the MLPD would ensure that Project implementation would not result in a significant in substantial adverse physical impacts associated with police protection services.
Mitigation Measures: No mitigation measures are required.
3) Schools?
No Impact. The Project involves development of a passenger terminal and does not involve the construction of new school facilities. Further, the Project does not involve new housing; therefore, a demand for new school facilities is not created.
Mitigation Measures: No mitigation measures are required.
4) Parks?
No Impact. The Project involves development of a passenger terminal and does not involve the construction of new parks or recreational facilities. Further, the Project does not involve new housing, therefore, a demand for new park facilities is not created.
Mitigation Measures: No mitigation measures are required.
5) Other public facilities?
No Impact. The Project involves development of a passenger terminal. Due to the nature and scope of the proposed development, Project implementation would not increase the demand for other public facilities such that it would create the need for alteration or construction of any governmental buildings or services.
Mitigation Measures: No mitigation measures are required.
4.14 RECREATION. a) Would the project increase the use of existing neighborhood and regional parks or other recreational facilities such that substantial physical deterioration of the facility would occur or be accelerated?
Less Than Significant Impact. The Project involves development of a passenger terminal and does not involve new housing. Therefore, Project implementation would not directly increase the use of existing recreational facilities, such that physical deterioration would occur.
The Project proposes to initiate scheduled commercial air service into the Airport (67,168 annual enplanements and 17,482 annual aircraft operations). The visitors arriving by air could potentially increase the use of existing recreational facilities. The developments that
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accommodate visitors would be required to implement the following goals and policies of the 2007 General Plan, pertaining to visitor population recreation:
P.4. Goal: Provide and encourage a wide variety of outdoor and indoor recreation readily accessible to residents and visitors of all ages.
P.4.A. Policy: Expand recreational opportunities by proactively developing partnerships with public agencies and private entities.
With implementation of the 2007 General Plan, impacts in this regard would be reduced to less than significant levels with regard to increased peak maximum daily population of people at one time.
Mitigation Measures: No mitigation measures are required. b) Does the project include recreational facilities or require the construction or expansion of recreational facilities, which might have an adverse physical effect on the environment?
Less Than Significant Impact. Refer to Response 4.13(a)(4).
Mitigation Measures: No mitigation measures are required.
4.15 TRANSPORTATION/TRAFFIC.
The findings of the 2002 Supplement (Pages III-64 to III-67) are summarized as follows:
When the intersection of U.S. Highway 395 at Hot Creek Road drops below level of service (LOS) D, mitigation is recommended. In this case, a traffic signal is not considered acceptable by Caltrans due in part to the high vehicular speeds along U.S. Highway 395; therefore, either minor intersection channelization is recommended or alternative access locations on U.S. Highway 395.
There would be increased traffic on U.S. Highway 395 and other highways in the region as a result of the growth in tourism. This might be offset on a micro scale by fewer tourists driving automobiles from farther airports or their homes, through which the air pollution emissions would be improved. The traffic congestion in the Town of Mammoth Lakes would also be reduced through the provision of bus service to the Airport as specified in memo on bus transportation provided in Appendix D (of the 2002 Supplement).
The Convict Lake Road is a direct emergency access point to the midpoint of the airfield from U.S. Highway 395…this emergency access point is adequate for emergency response requirements.
The proposed project would not cause a substantial increase in existing traffic and would not cause the level of service to deteriorate beyond standards established by Caltrans. Therefore, the project would have no adverse significant impact on transportation/traffic.
As stated above, the proposed project is not expected to cause any new significant impacts in relation to Transportation or Circulation; therefore, no new unavoidable significant impacts are anticipated.
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Would the Project: a) Cause an increase in traffic, which is substantial in relation to the existing traffic load and capacity of the street system (i.e., result in a substantial increase in either the number of vehicle trips, the volume to capacity ratio on roads, or congestion at intersections)?
Less Than Significant With Mitigation Incorporated. This discussion is based upon the Traffic Impact Analysis Mammoth Lake-Yosemite Valley Airport (LSA Associates, Inc., February 5, 2008), which is included as Appendix 9.3, Traffic Impact Analysis. The purpose of the Traffic Impact Analysis (TIA) is to assess the Airport Project’s short- and long-term impacts, and to consider the cumulative impacts of two relevant development projects: Hot Creek Resort and Sierra Business Park Specific Plan. The study examines conditions in Years 2006 and 2025 and considers growth in traffic along U.S. Highway 395. The following scenarios are evaluated in this analysis:
Existing Year 2006 Conditions; Existing Year 2006 Plus Project Conditions; Existing Year 2006 Plus Cumulative Conditions; Forecast Year 2025 Conditions; Forecast Year 2025 Plus Project Conditions; and Forecast Year 2025 Plus Cumulative Conditions.
REGULATORY SETTING
Analysis Methodology
The traffic analysis for the Project has been prepared to be generally consistent with the Guide for the Preparation of Traffic Impact Studies (Caltrans, December 2002). The Highway Capacity Software (HCS2000) was utilized to determine the LOS at the unsignalized intersection U.S. Highway 395/Hot Creek Fish Hatchery Road (Hot Creek Road). The HCS2000 software is consistent with the 2000 Highway Capacity Manual (HCM) methodology for the analysis of unsignalized intersections.
In previous traffic analyses dated November 2000, the 1997 HCM method was used to analyze the U.S. Highway 395/Hot Creek Road intersection. As a limitation of the 1997 HCM, the U.S. Highway 395/Hot Creek Road intersection was analyzed as two separate intersections due to the width of the existing median. However, the current HCS2000 software package is able to analyze U.S. Highway 395/Hot Creek Road as a single intersection with a “two-stage gap acceptance” process (Chapter 17 of the HCM2000).
The existing median along U.S. Highway 395 is approximately 70 feet wide. Assuming a standard vehicle length of 22 feet per vehicle, which includes front and rear clearance space, approximately three vehicles can be stored in the median. A vehicle queuing analysis has been conducted consistent with the HCM2000 methodology. The queuing analysis would determine the length of forecast vehicle queues at the U.S. Highway 395/Hot Creek Road intersection, specifically within the 70-foot wide median storage lanes. In particular, the northbound and southbound left turn queues from U.S. Highway 395 were analyzed to ensure that vehicles already stored within the median would not be blocked from their intended maneuvers. The time period analyzed for both intersections is the winter Friday PM peak hour, since this period would yield the greatest amount of traffic under cumulative conditions.
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Performance Criteria
According to Caltrans guidelines, the minimum acceptable level of service (LOS) for intersections is LOS D.
EXISTING YEAR 2006 CONDITIONS
Existing Circulation Network
Regional access to the proposed Project site (the Airport) is from U.S. Highway 395. North of the Project site, U.S. Highway 395 provides access to the Town of Mammoth Lakes and the Lake Tahoe region. South of the Project site, U.S. Highway 395 provides access to Crowley Lake, Bishop, and Southern California. Local access to the Airport is provided via Hot Creek Road. Hot Creek Road is an undivided, two lane road with an at-grade intersection with U.S. Highway 395.
Volumes and Levels of Services
The existing traffic volumes for the U.S. Highway 395 mainline were provided by the Caltrans 2006 Traffic and Vehicle Data Systems Unit. Peak hour traffic volumes on Hot Creek Road were based on a manual count collected by the Town on January 18, 2008, and are provided in Appendix 9.3.
Table T-1, Existing Intersection LOS Summary, presents the existing Year 2006 condition LOS for the study intersection (i.e., U.S. Highway 395 at Hot Creek Road). As indicated in Table T-1, the study intersection operates with a satisfactory LOS B (10.8 seconds) under existing year 2006 conditions; refer to Appendix 9.3 for the LOS worksheets.
IMPACT THRESHOLDS AND SIGNIFICANCE CRITERIA
According to Caltrans guidelines, the minimum acceptable LOS for intersections is LOS D. Therefore, when an intersection is forecast to operate at LOS E or LOS F, mitigation would be required to bring the intersection to LOS D or better.
EXISTING PLUS PROJECT CONDITIONS
Project Trip Generation and Assignment
Table T-2, Project Trip Generation, presents the Project’s trip generation. The Project proposes to conduct two daily flights, with flights carrying up to 78 passengers. Service in 2025 is projected to increase to a maximum of eight flights per day. To provide a conservative analysis, two flights are considered to occur during the PM peak hour (two flights arriving and two flights departing). This results in a maximum of 312 passengers (156 arrivals/156 departures) in the peak hour.
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Table T-1 Existing Intersection LOS Summary
U.S. Highway 395/Hot Creek Road1 Intersection Delay/LOS NB/SB Queue Lengths EB/WB Queue Lengths Scenario Max Max Max Approach LOS Movement Movement3 Delay2 Queue2 Queue2 With Existing Circulation System Existing Year 2006 Conditions4 11.6 WB B 0.05 Veh. SB-L 0.10 Veh. WB-LTR Sec.5 Notes: 1. Due to the current intersection configuration, the northbound and southbound approaches on U.S. Highway 395 are separate intersections. However, HCS2000 software allows for analysis of single intersection with a “two-stage” gap acceptance with 3 vehicles stored in median. 2. Intersections are analyzed through the Highway Capacity Manual (HCM) 2000 Operations Analysis. Delay is expressed in seconds of average delay per vehicle. LOS = Level of Service. Vehicle queues are expressed in numbers of vehicles. 3. SB-L movement consists of vehicles traveling south on U.S. Highway 395 turning left at Hot Creek Road destined to Airport, Hot Creek Resort and/or hot springs. EB- and WB-LTR movements consists of vehicles on Hot Creek Road destined towards its intersection with U.S. Highway 395. 4. Existing conditions are based on Caltrans 2006 counts on mainline segments, and manual PM peak hour counts on Hot Creek Road conducted in January, 2008. 5. Sec. = Seconds; WB = Westbound; Veh. = Vehicles; SB = Southbound; L = Left; TR = Turn. Source: LSA Associates, Mammoth Lakes-Yosemite Valley Airport Traffic Impact Analysis, February 5, 2008.
Table T-2 Project Trip Generation
PM Peak Hour Land Use Size / Units ADT In Out Total TRIP RATES Mammoth Lakes-Yosemite Valley Airport1 Based on data provided by Mammoth Lakes-Yosemite Valley Airport TRIP GENERATION Mammoth Lakes-Yosemite Valley Airport 312 passengers 400 50 50 100 1 Airport trip generation data provided by Mammoth Lakes-Yosemite Valley Airport staff (Tom Cornell-Ricondo). Source: LSA Associates, Mammoth Lakes-Yosemite Valley Airport Traffic Impact Analysis, February 5, 2008.
The introduction of commercial flights would generate approximately 100 PM peak hour trips. The traffic generated by these arriving and departing passengers would be accommodated by a combination of private vehicles, buses, shuttles/vans from major hotels, rental cars, and pick- up/drop-off private vehicles. For a conservative estimate, an overall passenger occupancy of 3.0 is projected for all vehicles, resulting in approximately 50 inbound and 50 outbound vehicles to service two fully-loaded 78-passenger planes in the peak hour.
As indicated in Table T-2, the Project would generate a total of 400 daily trips and 100 PM peak hour trips (50 inbound and 50 outbound). It is anticipated that all PM peak hour trips associated with the Airport would originate from and be destined to the Town of Mammoth Lakes.
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Proposed Improvements
As part of the initiation of commercial service at the Airport, the Project proposes minor improvements at the U.S. Highway 395 intersection with Hot Creek Road. Those improvements include both northbound U.S. Highway 395 right turn deceleration and acceleration lanes and the lengthening of the southbound U.S. Highway 395 left turn deceleration lane. These proposed improvements would be consistent with the design requirements of Topic 405 – Intersection Design Standards of the Highway Design Manual (July 1, 1995).
Volumes and Levels of Services
The existing traffic volumes at the U.S. Highway 395/Hot Creek Road intersection were added to the Project trip assignments discussed above, and intersection LOS were determined. Table T-3, Existing Plus Project Intersection LOS Summary, presents the existing Year 2006 plus Project condition LOS for the study intersection. As indicated in Table T-3, the study intersection is forecast to operate with satisfactory LOS (LOS D or better) under existing year 2006 plus Project conditions; refer to Appendix 9.3 for the LOS worksheets.
Table T-3 Existing Plus Project Intersection LOS Summary
U.S. Highway 395/Hot Creek Road1 Intersection Delay/LOS NB/SB Queue Lengths EB/WB Queue Lengths Scenario Max Max Max Approach LOS Movement Movement3 Delay2 Queue2 Queue2 With Existing Circulation System Existing Year 2006 Conditions4 11.6 WB B 0.05 Veh. SB-L 0.10 Veh. WB-LTR Sec.5 Existing + Project 11.4 WB B 0.22 Veh. SB-L 0.37 Veh. WB-LTR Sec. Notes: 1. Due to the current intersection configuration, the northbound and southbound approaches on U.S. Highway 395 are separate intersections. However, HCS2000 software allows for analysis of single intersection with a “two-stage” gap acceptance with 3 vehicles stored in median. 2. Intersections are analyzed through the Highway Capacity Manual (HCM) 2000 Operations Analysis. Delay is expressed in seconds of average delay per vehicle. LOS = Level of Service. Vehicle queues are expressed in numbers of vehicles. 3. SB-L movement consists of vehicles traveling south on U.S. Highway 395 turning left at Hot Creek Road destined to Airport, Hot Creek Resort and/or hot springs. EB- and WB-LTR movements consists of vehicles on Hot Creek Road destined towards its intersection with U.S. 395. 4. Existing conditions are based on Caltrans 2006 counts on mainline segments, and manual PM peak hour counts on Hot Creek Road conducted in January, 2008. 5. Sec. = Seconds; WB = Westbound; Veh. = Vehicles; SB = Southbound; L = Left; TR = Turn. Source: LSA Associates, Mammoth Lakes-Yosemite Valley Airport Traffic Impact Analysis, February 5, 2008.
EXISTING PLUS CUMULATIVE CONDITIONS
Cumulative Projects Trip Generation and Assignment
As previously noted, the TIA assesses the Project’s short- and long-term impacts, as well as the cumulative impacts of two relevant development projects: Hot Creek Resort and Sierra Business Park Specific Plan.
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Hot Creek Resort
The trip generation estimates for the Hot Creek Resort aviation mixed-use development are based on trip rates provided in the Institute of Transportation Engineers’ (ITE) Trip Generation, 6th Edition (1997). Based on the description of the lodging component of the Hot Creek resort, a total of 188 multifamily townhomes, a 62-room hotel, and a 100-site RV park would be developed. An 80 percent occupancy rate was factored for these lodging type land uses to account for the “typical” winter conditions consistent with Town of Mammoth Lakes methodology. Therefore, trips were generated for Hot Creek Resort’s lodging component, which consisted of 150 multifamily townhomes, a 50-room hotel, and an 80-site RV park during the “typical” winter condition. Table T-4, Cumulative Trip Generation, presents the cumulative project’s trip generation. As indicated in Table T-4, the approved Hot Creek Resort would generate a total of 6,355 daily trips and 542 PM peak hour trips.
In addition to the 80 percent occupancy factor for the lodging components, trip reductions for the multifamily rental townhomes and hotel were applied due to the available shuttle service for residents of the townhomes and hotel guests to the resort areas of the Town (i.e., Mammoth Mountain Ski Area [MMSA]). The planned shuttle service would be available to guests of the townhomes and hotel on a regular basis throughout the day, and would be operated to minimize passenger vehicle traffic between the Hot Creek Resort and the MMSA. A 60 percent reduction was applied to the trip generation of the townhomes; a 75 percent reduction was applied to the hotel’s trip generation estimates.
To account for the pass-by trip making for the retail components of Hot Creek Road, a 90 percent reduction in new trips generated by the gas station and a 25 percent reduction in new trips generated by the restaurant were applied. In addition, a 75 percent reduction in restaurant trips was applied for the internal trip capture of lodging residents and Airport patrons who would utilize the restaurants on site. It should be noted that 100 percent of the restaurant trips were removed from the overall trip generation (75 percent via internal trip capture and 25 percent via pass-by trips). Based on the reductions for occupancy, shuttle service, pass-by trip making, and internal trip capture, a total of 5,053 daily and 425 PM peak hour trips were removed from the total Hot Creek Resort total trip generation. Therefore, as indicated in Table T-4, the Hot Creek Resort would generate approximately 1,302 new daily trips and a 117 new PM peak hour trips.
It should be noted that reductions on the northbound and southbound through movements on U.S. Highway 395 were made to account for the pass-by trips of the gas station and restaurant components. More specifically, a pass-by trip is a through trip that is diverted into the project via southbound left or northbound right turn and then reassigned to U.S. Highway 395 via another right or left turn back onto U.S. Highway 395.
Sierra Business Park Specific Plan
Trip generation estimates and the trip assignment for the Sierra Business Park were obtained from the traffic impact study addendum completed by Traffic Safety Engineers (TSE). Appendix 9.3 contains the trip generation and trip assignment completed for this specific project. As indicated in Table T-4, the Sierra Business Park would generate 1,487 daily trips, and 229 PM peak hour trips.
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Table T-4 Cumulative Trip Generation
PM Peak Hour Land Use Size / Units ADT In Out Total TRIP RATES Mammoth Lakes-Yosemite Valley Airport1 Based on data provided by Mammoth Lakes-Yosemite Valley Airport Hot Creek Resort Aviation Mixed-Used Development2 Gasoline/Service Station w/ Convenience Market Per fueling position (FP) 162.78 6.69 6.69 13.38 Residential High Density (MF) Seasonal Per dwelling unit (DU) 8.00 0.50 0.25 0.75 Hotel Per occupied room 8.92 0.35 0.36 0.71 Campground/Recreational Vehicle Park Per occupied campsite 4.00 0.20 0.20 0.39 High Turnover Sit-Down Restaurant Per seat 4.83 0.24 0.18 0.42 Sierra Business Park Specific Plan3 Based on data provided in Morgan Industrial Park Specific Plan TIA TRIP GENERATION Mammoth Lakes-Yosemite Valley Airport 312 passengers 400 50 50 100 Hot Creek Resort Aviation Mixed-Used Development Gasoline/Service Station w/ Convenience Market 24 FPs 3,907 161 161 321 Residential High Density (MF) Seasonal4 150 DUs 1,203 76 37 113 Hotel4 50 Rooms 442 17 18 35 Campground/Recreational Vehicle Park4 80 Campsites 320 16 16 31 High Turnover Sit-Down Restaurant 100 Seats 483 24 18 42 Sierra Business Park Specific Plan 36 Acres 1,487 48 181 229 Total Trip Generation 8,242 391 480 871 TRIP REDUCTIONS Hot Creek Resort Aviation Mixed-Used Development Gasoline/Service Station w/ Convenience Market5 90 percent reduction -3,516 -145 -145 -289 Residential High Density (MF) Seasonal6 60 percent reduction -722 -45 -22 -68 Hotel7 75 percent reduction -332 -13 -13 -26 Campground/Recreational Vehicle Park No trip reductions anticipated High Turnover Sit-Down Restaurant8 100 percent reduction -483 -24 -18 -42 Total Trip Reductions -5,053 -227 -198 -425 NET EFFECTIVE TRIP GENERATION 3,190 164 282 446 Notes: 1. Airport trip generation data provided by Mammoth Lakes-Yosemite Valley Airport staff (Tom Cornell-Ricondo). 2. Trip rates for Hot Creek Resort Mixed-Use Development provided in Trip Generation, 6th Edition, Institute of Transportation Engineers (ITE), 1997. Trip rates for the Residential High Density (MF) Seasonal are based on the Mammoth Lakes Transportation Model (MTM). Daily trip rate for RV Park based on ITE rates 3. Trip generation data provided in Traffic Impact Study Addendum for Sierra Business Park Specific Plan, Traffic Safety Engineers (TSE), November 2000. 4. Unit counts for residential/lodging components are based on 80% occupancy rate which is consistent with Town of Mammoth “typical” winter conditions. Build out unit counts are 188 multi-family homes, 62 hotel rooms, and 100 campsites. 5. A 90% reduction was applied due to a majority of pass-by trip making fro vehicles traveling on U.S. Highway 395. Approximately 10% (new trips) may originate from existing communities south of the Airport. 6. A 60% reduction was applied due to shuttle service provided to residents destined to Mammoth Lakes and Mammoth Mountain Ski Area. A majority of residents would arrive to the Hot Creek Resort Mixed-Use development via airline service to Mammoth Lakes- Yosemite Valley Airport. 7. A 75% reduction was applied due to shuttle service provided to residents destined to Mammoth Lakes and Mammoth Mountain Ski Area. A majority of residents would arrive to the Hot Creek Resort Mixed-Use development via airline service to Mammoth Lakes- Yosemite Valley Airport. 8. A 75% internal trip capture, and 25% pass-by trip reduction was applied for vehicles traveling on U.S. Highway 395. No new trips are anticipated for this land use. Source: LSA Associates, Mammoth Lakes-Yosemite Valley Airport Traffic Impact Analysis, February 5, 2008.
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Cumulative Trip Generation
As indicated in Table T-4, the existing Year 2006 plus cumulative projects are estimated to generate a total of 8,241 daily trips and 871 PM peak hour trips (391 inbound and 480 outbound). With the trip reductions for the occupancy, shuttle service, pass-by trip making, and internal trip capture for the components of the Hot Creek Resort development applied to the total trip generation, the new cumulative trips are 3,189 daily trips and 446 PM peak hour trips (164 inbound and 282 outbound).
Volumes and Levels of Services
The existing Year 2006 traffic volumes at the U.S. Highway 395/Hot Creek Road intersection were added to the cumulative projects trip assignments discussed above, and intersection LOS were determined for the existing Year 2006 plus cumulative condition. Table T-5, Existing Plus Cumulative Intersection LOS Summary, presents the existing Year 2006 plus cumulative conditions LOS for the northbound and southbound study intersection. As indicated in Table T- 5, the study intersection is forecast to operate with satisfactory LOS (LOS D or better) under existing Year 2006 plus cumulative conditions.
Table T-5 Year 2006 Cumulative Intersection LOS Summary
U.S. Highway 395/Hot Creek Road1 Intersection Delay/LOS NB/SB Queue Lengths EB/WB Queue Lengths Scenario Max Max Max Approach LOS Movement Movement3 Delay2 Queue2 Queue2 With Existing Circulation System Existing Year 2006 Conditions4 11.6 WB B 0.05 Veh. SB-L 0.10 Veh. WB-LTR Sec. Existing + Project 11.4 WB B 0.22 Veh. SB-L 0.37 Veh. WB-LTR Sec. Existing + Cumulative 28.2 EB D 0.61 Veh. SB-L 3.38 Veh. EB-LTR Sec. Notes: 1. Due to the current intersection configuration, the northbound and southbound approaches on U.S. Highway 395 are separate intersections. However, HCS2000 software allows for analysis of single intersection with a “two-stage” gap acceptance with 3 vehicles stored in median. 2. Intersections are analyzed through the Highway Capacity Manual (HCM) 2000 Operations Analysis. Delay is expressed in seconds of average delay per vehicle. LOS = Level of Service. Vehicle queues are expressed in numbers of vehicles. 3. SB-L movement consists of vehicles traveling south on U.S. Highway 395 turning left at Hot Creek Road destined to Airport, Hot Creek Resort and/or hot springs. EB- and WB-LTR movements consists of vehicles on Hot Creek Road destined towards its intersection with U.S. 395. 4. Existing conditions are based on Caltrans 2006 counts on mainline segments, and manual PM peak hour counts on Hot Creek Road conducted in January, 2008. 5. Sec. = Seconds; WB = Westbound; EB = Eastbound; Veh. = Vehicles; SB = Southbound; L = Left; TR = Turn. Source: LSA Associates, Mammoth Lakes-Yosemite Valley Airport Traffic Impact Analysis, February 5, 2008.
FORECAST YEAR 2025 CONDITIONS
Per direction by Caltrans staff (Tom Meyers - District 9), a 1.0 percent annual growth rate, compounded, was applied to the northbound and southbound through volumes for U.S. Highway 395. This rate constitutes a growth of 21 percent from Years 2006 to 2025.
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Volumes and Levels of Services
Existing geometrics were assumed for the forecast Year 2025 condition. Table T-6, Year 2025 Intersection LOS Summary, presents the forecast Year 2025 LOS for the northbound and southbound study intersection. As indicated in Table T-6, the study intersection is forecast to continue to operate with a satisfactory LOS B (12.5 seconds) under forecast Year 2025 conditions; refer to Appendix 9.3 for the LOS worksheets.
Table T-6 Year 2025 Intersection LOS Summary
U.S. Highway 395/Hot Creek Road1 Intersection Delay/LOS NB/SB Queue Lengths EB/WB Queue Lengths Scenario Max Approach LOS Max Queue2 Movement Max Queue2 Movement3 Delay2 With Existing Circulation System Year 2025 Baseline Conditions4 12.5 sec. WB B 0.04 veh. SB-L 0.12 veh. WB-LTR Notes: 1 Due to the current intersection configuration, the northbound and southbound approaches on U.S. Highway 395 are separate intersections. However, HCS2000 software allows for analysis of single intersection with a “two-stage” gap acceptance with 3 vehicles stored in median. 2 Intersections are analyzed through the Highway Capacity Manual (HCM) 2000 Operations Analysis. Delay is expressed in seconds of average delay per vehicle. LOS = Level of Service. Vehicle queues are expressed in numbers of vehicles. 3 SB-L movement consists of vehicles traveling south on U.S. Highway 395 turning left at Hot Creek Road destined to Airport, Hot Creek Resort and/or hot springs. EB- and WB-LTR movements consists of vehicles on Hot Creek Road destined towards its intersection with U.S. Highway 395. 4 Per Caltrans, District 9, a 1.0% per year growth rate compounded annually was used to determine the 2025 baseline volumes on U.S. Highway 395. This rate constitutes a growth of 21.0% from 2006 to 2025. Source: LSA Associates, Mammoth Lakes-Yosemite Valley Airport Traffic Impact Analysis, February 5, 2008.
FORECAST YEAR 2025 PLUS PROJECT CONDITIONS
Volumes and Levels of Services
The forecast Year 2025 traffic volumes at the U.S. Highway 395/Hot Creek Road intersection (northbound and southbound) were added to the Project trip assignments discussed previously, and intersection LOS were determined for the forecast year 2025 plus Project condition. Appendix 9.3 contains the LOS worksheets. Table T-7, Year 2025 Plus Project Intersection LOS Summary, presents the forecast Year 2025 plus Project condition LOS for the northbound and southbound study intersection. As indicated in Table T-7, the study intersection is forecast to operate with satisfactory LOS (LOS D or better) under forecast Year 2025 plus Project conditions.
FORECAST YEAR 2025 PLUS CUMULATIVE CONDITIONS
Volumes and Levels of Services
The forecast Year 2025 baseline traffic volumes at the U.S. Highway 395/Hot Creek Road intersection (northbound and southbound) were added to the cumulative project trip assignments discussed previously, and intersection LOS were determined for the forecast year 2025 plus cumulative condition; refer to Appendix 9.3 for the LOS worksheets.
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Table T-7 presents the forecast Year 2025 plus cumulative conditions LOS for the northbound and southbound study intersection. As indicated in Table T-7, the forecast Year 2025 plus cumulative condition is forecast to operate at LOS E (36.3 seconds) due to the volume and delay of eastbound left turning vehicles from the Sierra Business Park, and eastbound through traffic volumes destined to the Airport and the Hot Creek Resort. Mitigation measures are required for the forecast year 2025 plus cumulative condition to bring the U.S. Highway 395/Hot Creek Road intersection to LOS D or better.
Table T-7 Year 2025 Plus Project Intersection LOS Summary
U.S. Highway 395/Hot Creek Road1 Intersection Delay/LOS NB/SB Queue Lengths EB/WB Queue Lengths Scenario Max Max Max Approach LOS Movement Movement3 Delay2 Queue2 Queue2 With Existing Circulation System Year 2025 Baseline Conditions4 12.5 sec. WB B 0.04 veh. SB-L 0.12 veh. WB-LTR 2025 plus Project 12.2 sec. WB B 0.26 veh. SB-L 0.41 veh. WB-LTR 2025 plus Cumulative Projects 41.2 sec. EB E 0.70 veh. SB-L 5.07 veh. EB-LTR – With Mitigation 33.5 sec. EB D 0.70 veh. SB-L 3.82 veh. EB-L Notes: 1. Due to the current intersection configuration, the northbound and southbound approaches on U.S. Highway 395 are separate intersections. However, HCS2000 software allows for analysis of single intersection with a “two-stage” gap acceptance with 3 vehicles stored in median. 2. Intersections are analyzed through the Highway Capacity Manual (HCM) 2000 Operations Analysis. Delay is expressed in seconds of average delay per vehicle. LOS = Level of Service. Vehicle queues are expressed in numbers of vehicles. 3. SB-L movement consists of vehicles traveling south on U.S. Highway 395 turning left at Hot Creek Road destined to Airport, Hot Creek Resort and/or hot springs. EB- and WB-LTR movements consists of vehicles on Hot Creek Road destined towards its intersection with U.S. Highway 395. 4. Per Caltrans, District 9, a 1.0% per year growth rate compounded annually was used to determine the 2025 baseline volumes on U.S. Highway 395. This rate constitutes a growth of 21.0% from 2006 to 2025. 5. Sec. = Seconds; WB = Westbound; EB = Eastbound; Veh. = Vehicles; SB = Southbound; L = Left; TR = Turn. Source: LSA Associates, Mammoth Lakes-Yosemite Valley Airport Traffic Impact Analysis, February 5, 2008.
FORECAST YEAR 2025 PLUS CUMULATIVE MITIGATED CONDITIONS
Volumes and Levels of Services
When the intersection of U.S. Highway 395 at Hot Creek Road drops below LOS (LOS) D, mitigation is recommended. In this case, a traffic signal is not considered acceptable by Caltrans due in part to the high vehicular speeds; therefore, minor intersection channelization is recommended. It is noted, the Hot Creek Resort project is adjacent to the Airport and includes a hotel and restaurant, and is in litigation. If the Hot Creek Resort project were not to become operational, no mitigation would be necessary for the proposed Project and Hot Creek Resort.
Mitigation in the form of restriping the center median lanes to provide separate eastbound and westbound left and through lanes would be required to reduce the impacts and maintain LOS D or better conditions. A minimum nose-to-nose width of 48 feet in the median is required to provide separate eastbound and westbound left and through lanes.
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Table T-7 presents the forecast Year 2025 plus cumulative mitigated condition LOS for the study intersection. As indicated in Table T-7, the study intersection would operate with satisfactory LOS (LOS D or better) under the forecast Year 2025 plus cumulative mitigated conditions. Therefore, Project implementation would not cause an increase in traffic, which is substantial in relation to the existing traffic load and capacity of the street system or exceed an established LOS standard. A less than significant impact would occur in this regard.
The specific phasing and absorption of each cumulative project cannot be reasonably projected at this time and, therefore, specific timing for the implementation of the alternative mitigation measures cannot be specified. However, to provide assurance that adequate LOS is maintained for capacity and safety benefits, an annual monitoring program is recommended.
The annual monitoring reports would be conducted by the Town and would begin at the onset of commercial service at the Airport. The monitoring reports would document the traffic counts and LOS at the Hot Creek Road intersection with U.S. Highway 395. Upon completion, the monitoring reports would be submitted to Caltrans for review and approval. The objective of the monitoring reports would be to implement mitigation measures prior to reaching LOS E. To achieve this, Caltrans project development activities for either mitigation measure would be initiated when LOS D is reached. It is further recommended that both summer and winter conditions be reported and that the monitoring program objective be aimed at collecting peak and/or design level traffic data.
The costs of the mitigation (restriping the center median) would be spread to the contributing projects on a proportionate basis in relation to their respective peak hour trip generation.
Mitigation Measures:
TR-1 As part of the initiation of commercial service at the Airport, minor improvements shall be implemented at the U.S. Highway 395 intersection with Hot Creek Road. Those improvements, which are proposed to include both northbound U.S. Highway 395 right turn deceleration and acceleration lanes and the lengthening of the southbound U.S. Highway 395 left turn deceleration lane, shall be consistent with the design requirements of Topic 405 – Intersection Design Standards of the Highway Design Manual (July 1, 1995).
TR-2 To provide assurance that adequate LOS is maintained for capacity and safety benefits, an annual monitoring program shall be conducted by the Town of Mammoth Lakes and shall be implemented at the U.S. Highway 395 intersection with Hot Creek Road. The annual monitoring reports shall begin at the onset of commercial service at the Airport and shall record the traffic counts and LOS at the Hot Creek Road intersection with U.S. Highway 395. Upon completion, the annual monitoring reports shall be submitted to Caltrans for review and approval. Both summer and winter conditions shall be reported. The monitoring program shall collect peak and/or design level traffic data. The objective of the monitoring reports shall be to implement mitigation measures prior to reaching LOS E. The Caltrans project development activities for the mitigation shall be initiated when LOS D is reached.
TR-3 When the intersection of U.S. Highway 395 at Hot Creek Road drops below LOS (LOS) D, as determined by implementation of Mitigation Measure TR-2, minor intersection channelization shall be implemented. Specifically, the center median lanes shall be restriped to provide separate eastbound and westbound left and
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through lanes. A minimum nose-to-nose width of 48 feet in the median shall be provided to separate eastbound and westbound left and through lanes. The costs of restriping the center median shall be spread to the contributing projects on a proportionate basis in relation to their respective peak hour trip generation. If the Hot Creek Resort project were not be become operational, no mitigation shall be required for the proposed Project and the Hot Creek Resort. b) Exceed, either individually or cumulatively, a level of service standard established by the Town for designated roads or highways?
Less Than Significant With Mitigation Incorporated. Refer to Response 4.15(a).
Mitigation Measures: No mitigation measures are required. c) Result in a change in air traffic patterns, including either an increase in traffic levels or a change in location that results in substantial safety risks?
Less Than Significant Impact. Project implementation would result in a change in air traffic patterns and an increase in air traffic levels. As concluded in Response 4.7(e), Project implementation would not result in substantial safety risks.
Mitigation Measures: No mitigation measures are required. d) Substantially increase hazards due to a design feature (e.g., sharp curves or dangerous intersections) or incompatible uses (e.g., farm equipment)?
Less Than Significant Impact. Refer to Response 4.7(e).
Mitigation Measures: No mitigation measures are required. e) Result in inadequate emergency access?
Less Than Significant Impact. Refer to Response 4.7(e).
Mitigation Measures: No mitigation measures are required. f) Results in inadequate parking capacity?
No Impact. According to the 2002 Supplement, there are 56 existing parking spaces at the Airport. This is composed of 10 stalls for employees, 26 for the passenger terminal, and 20 for other transient services. It is assumed that there will be a total of nine employees at the Airport, and that a majority of the passengers will be tourists and will take public transportation into Town. Therefore, there is not a need to build any additional parking capacity as the current supply is sufficient to the anticipated needs.
Mitigation Measures: No mitigation measures are required.
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g) Conflict with adopted policies, plans, or programs supporting alternative transportation (e.g., bus turnouts, bicycle racks)?
No Impact. Overall, the Project proposes to conduct two daily flights, with flights carrying up to 78 passengers. Service in 2015 is projected to increase to a maximum of eight flights per day. The introduction of commercial flights would generate approximately 100 PM peak hour trips. The traffic generated by these arriving and departing passengers would be accommodated by a combination of private vehicles, buses, shuttles/vans from major hotels, rental cars, and pick- up/drop-off private vehicles. It should be noted that these transportation services are already in place throughout the Town, and that additional shuttle/bus services would not be necessary. Also, the Airport currently has a rental car facility should passengers desire to utilize that mode of transportation. Therefore, there would be no impacts in this regard.
Mitigation Measures: No mitigation measures are required.
4.16 UTILITIES AND SERVICE SYSTEMS.
The findings of the 2002 Supplement (Page III-97) are summarized as follows:
…..by 2022, 910 pounds of waste per day may ultimately be generated by the increased air traffic….. depending upon the type of services provided in an expanded terminal, the waste generation rate would at least double, bringing the total waste generation at the facility to an estimated 1,820 pounds per day by 2022.
…..the existing permitted landfill capacity will be able to accommodate an increase in the solid waste of 10 tons per day. Accordingly, the quantity of waste that may potentially be generated at an expanded Mammoth Yosemite Airport would not have a significant impact on County Landfills.
…..the proposed project would not have any significant adverse impacts on utilities as it does not substantially increase the demand such that existing or planned capacity of distribution systems or available supply would be exceeded.
Would the Project: a) Exceed wastewater treatment requirements of the applicable Regional Water Quality Control Board?
Less Than Significant Impact. The 2002 Project involved 333,000 annual enplanements and 23,650 annual aircraft operations, as well as various physical improvements to the Airport, including a new 25,000-SF passenger terminal, among others. The 2002 Supplement concluded that the proposed Project would not have any significant adverse impacts on utilities, as it would not substantially increase the demand such that existing or planned capacity of distribution systems or available supply would be exceeded.
The current Project considers 67,168 annual enplanements, 17,482 annual aircraft operations, and involves remodeling the existing maintenance building for use as a passenger terminal. No new facilities would be constructed. Comparatively, the current Project represents approximately 80 percent fewer enplanements and approximately 26 percent fewer aircraft operations, than the project analyzed in the 2002 Supplement. Project implementation would
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result in no greater impacts involving wastewater than previously identified in the 2002 Supplement and conditions have not changed. Therefore, Project implementation would not exceed wastewater treatment requirements or require construction of new wastewater treatment facilities; refer to Response 4.6(e).
Mitigation Measures: No mitigation measures are required. b) Require or result in the construction of new water or wastewater treatment facilities or expansion of existing facilities, the construction of which could cause significant environmental effects?
Less Than Significant Impact. Refer to Response 4.16(a).
Mitigation Measures: No mitigation measures are required. c) Require or result in the construction of new storm water drainage facilities or expansion of existing facilities, the construction of which could cause significant environmental effects?
Less Than Significant With Mitigation Incorporated. Refer to Response 4.8(c).
Mitigation Measures: No mitigation measures are required. d) Have sufficient water supplies available to serve the project from existing entitlements and resources, or are new or expanded entitlements needed?
Less Than Significant Impact. Refer to Response 4.16(a).
Mitigation Measures: No mitigation measures are required. e) Result in a determination by the wastewater treatment provider, which serves or may serve the project that it has adequate capacity to serve the project’s projected demand in addition to the provider’s existing commitments?
Less Than Significant Impact. Refer to Response 4.16(a).
Mitigation Measures: No mitigation measures are required. f) Be served by a landfill with sufficient permitted capacity to accommodate the project’s solid waste disposal needs?
Less Than Significant Impact. The 2002 Supplement concluded that the solid waste generation from the increased air traffic would be an estimated 1,820 pounds per day and that the existing permitted landfill capacity would be able to accommodate the increase. The 2002 Project involved 333,000 annual enplanements and 23,650 annual aircraft operations, as well as various physical improvements to the Airport, including a new 25,000-SF passenger terminal, among others. The current Project considers 67,168 annual enplanements, 17,482 annual aircraft operations, and involves remodeling the existing maintenance building for use as a passenger terminal. No new facilities would be constructed. Comparatively, the current Project represents approximately 80 percent fewer enplanements and approximately 26 percent fewer aircraft operations, than the project analyzed in the 2002 Supplement. Project implementation
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would result in no greater impacts involving solid waste generation than previously identified in the 2002 Supplement and conditions have not changed. Therefore, Project implementation would not result in significant impacts upon the landfill’s permitted capacity.
Mitigation Measures: No mitigation measures are required. g) Comply with federal, state and local statutes and regulations related to solid waste?
Less Than Significant Impact. The Project is required to comply with adopted programs and regulations pertaining to solid waste. Refer also to Response 4.16(f).
Mitigation Measures: No mitigation measures are required.
4.17 MANDATORY FINDINGS OF SIGNIFICANCE. a) Does the project have the potential to degrade the quality of the environment, substantially reduce the habitat of a fish or wildlife species, cause a fish or wildlife population to drop below self-sustaining levels, threaten to eliminate a plant or animal community, reduce the number or restrict the range of a rare or endangered plant or animal or eliminate important examples of the major periods of California history or prehistory?
Less Than Significant Impact. Based on the analysis contained in this Initial Study, the Project would not have a significant impact to biological or cultural/paleontological resources; refer to Responses 4.4 and 4.5, respectively. b) Does the project have impacts that are individually limited, but cumulatively considerable? (“Cumulatively considerable” means that the incremental effects of a project are considerable when viewed in connection with the effects of past projects, the effects of other current projects, and the effects of probable future projects)?
Less Than Significant Impact. For the purposes of the Traffic Impact Analysis, the proposed Project’s short- and long-term impacts, as well as cumulative impacts, were considered. The cumulative projects involved the Hot Creek Resort and Sierra Business Park. It is noted that these projects were also considered in the 2002 Supplement. Due to the nature and scope of the proposed aircraft operations, Project implementation would not result in impacts that are individually limited, but cumulatively considerable. c) Does the project have environmental effects, which will cause substantial adverse effects on human beings, either directly or indirectly?
Less Than Significant Impact. Previous sections of this IS/MND reviewed the proposed Project’s potential impacts related to aesthetics, air pollution, noise, public health and safety, traffic, and other issues. As concluded in these previous discussions, the proposed Project would result in less than significant environmental impact with implementation of the recommended mitigation measures. Therefore, the proposed Project would not result in environmental impacts that would cause substantial adverse effects on human beings.
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5.0 INVENTORY OF MITIGATION MEASURES
AESTHETICS
AES-1 The use of earth tone colors and natural materials shall be emphasized in the terminal’s design in order to enhance compatibility with the natural setting, subject to Design Review approval by the Town’s Planning Commission. (2002 Supplement, Mitigation Type: 3).
TRANSPORTATION/TRAFFIC
TR-1 As part of the initiation of commercial service at the Airport, minor improvements shall be implemented at the U.S. Highway 395 intersection with Hot Creek Road. Those improvements, which are proposed to include both northbound U.S. Highway 395 right turn deceleration and acceleration lanes and the lengthening of the southbound U.S. Highway 395 left turn deceleration lane, shall be consistent with the design requirements of Topic 405 – Intersection Design Standards of the Highway Design Manual (July 1, 1995).
TR-2 To provide assurance that adequate LOS is maintained for capacity and safety benefits, an annual monitoring program shall be conducted by the Town of Mammoth Lakes and shall be implemented at the U.S. Highway 395 intersection with Hot Creek Road. The annual monitoring reports shall begin at the onset of commercial service at the Airport and shall record the traffic counts and LOS at the Hot Creek Road intersection with U.S. Highway 395. Upon completion, the annual monitoring reports shall be submitted to Caltrans for review and approval. Both summer and winter conditions shall be reported. The monitoring program shall collect peak and/or design level traffic data. The objective of the monitoring reports shall be to implement mitigation measures prior to reaching LOS E. The Caltrans project development activities for the mitigation shall be initiated when LOS D is reached.
TR-3 When the intersection of U.S. Highway 395 at Hot Creek Road drops below LOS (LOS) D, as determined by implementation of Mitigation Measure TR-2, minor intersection channelization shall be implemented. Specifically, the center median lanes shall be restriped to provide separate eastbound and westbound left and through lanes. A minimum nose-to-nose width of 48 feet in the median shall be provided to separate eastbound and westbound left and through lanes. The costs of restriping the center median shall be spread to the contributing projects on a proportionate basis in relation to their respective peak hour trip generation. If the Hot Creek Resort project were not be become operational, no mitigation shall be required for the proposed Project and the Hot Creek Resort.
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6.0 REFERENCES
The following references were utilized during preparation of this Initial Study. These documents are available for review at the Town of Mammoth Lakes, 437 Old Mammoth Road, Suite R, Mammoth Lakes, California 93546.
1. American Association of State Climatologists, Policy Statement on Climate Variability and Change, February 2, 2002.
2. American Meteorological Society Atmospheric News, NOAA Arctic ‘Report Card’ Shows Continued Climate Changes, October 17, 2007.
3. California Department of Water Resources, Progress on Incorporating Climate Change into Management of California’s Water Resources, July 2006.
4. Great Basin Unified Air Quality Management District, Air Quality Management Plan for the Town of Mammoth Lakes, 1990.
5. Intergovernmental Panel on Climate Change, Climate Change 2001: Synthesis Report. A Contribution of Working Groups I, II, and III to the Third Assessment Report of the Intergovernmental Panel on Climate Change, 2001.
6. Intergovernmental Panel on Climate Change, Climate Change 2007: The Physical Science Basis, Summary for Policymakers, February 2007.
7. LSA Associates, Mammoth Lakes-Yosemite Valley Airport Traffic Impact Analysis, February 5, 2008.
8. Mono County Airport Land Use Commission, Environmental Impact Report and Environmental Assessment Mammoth/June Lakes Airport Land Use Plan, July 1986.
9. National Research Council, Radiative Forcing of Climate Change: Expanding the Concept and Addressing Uncertainties, 2005.
10. State of California, Department of Finance, E-5 Population and Housing Estimates for Cities, Counties and the State, 2001-2007, with 2000 Benchmark. Sacramento, California, May 2007.
11. Town of Mammoth Lakes, Final Supplement to Subsequent Environmental Impact Report, March 2002.
12. Town of Mammoth Lakes, Final Supplement to Subsequent Environmental Impact Report Mammoth Yosemite Airport Expansion Project Mammoth Yosemite Airport, March 2002.
13. Town of Mammoth Lakes Municipal Code, Updated April 2006.
14. Town of Mammoth Lakes, Mammoth Lakes Airport Expansion, Subsequent Environmental Impact Report and Updated Environmental Assessment, 1997.
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15. Town of Mammoth Lakes, Town of Mammoth Lakes General Plan 2007, August 2007.
16. Town of Mammoth Lakes, Town of Mammoth Lakes 2005 General Plan Update Final Program Environmental Impact Report, May 2007.
17. U.S. Department of Transportation Federal Aviation Administration Office and Environment and Energy, Consideration of Air Quality Impacts by Airplane Operations at or above 3,000 feet AGL, September 2000.
18. U.S. Department of Transportation Federal Aviation Administration, Draft Environmental Impact Statement Request For Operations Specifications Amendment By Horizon Air to Provide Scheduled Air Service to Mammoth Yosemite Airport, November 2007.
19. U.S. Department of Transportation Federal Aviation Administration, Mammoth Yosemite Airport Expansion Project Final Environmental Assessment, December 2000.
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7.0 REPORT PREPARATION PERSONNEL
Town of Mammoth Lakes (Lead Agency) Post Office Box 1609 437 Old Mammoth Road, Suite R Mammoth Lakes, Ca 93546 760.934.8989
Ms. Karen Johnston, Assistant Town Manager Ms. Ellen Clark, Senior Planner Mr. Peter Bernasconi, PE, Associate Civil Engineer
RBF Consulting (Environmental Analysis) 14725 Alton Parkway Irvine, California 92618 949.472.3505
Mr. Glenn Lajoie, AICP, Vice President, Environmental Services Mr. Eddie Torres, INCE, Project Manager Ms. Rita Garcia, Senior Environmental Analyst Mr. Achilles Malisos, Environmental Analyst Ms. Kristen Bogue, Environmental Analyst Ms. Michelle Dunn, Air Quality Specialist Ms. Linda Bo, Document Preparation/Graphic Artist
LSA Associates (Traffic Analysis) 20 Executive Park, Suite 200 Irvine, California 92614
Mr. Les Card, P.E., Principal Mr. Mike Arzibal, Project Engineer
Morrison Foerster 425 Market Street San Francisco, California 94105-2482
Mr. Zane O. Gresham, Attorney at Law
Baird Holm 1500 Woodmen Tower Omaha, Nebraska 68102
Mr. David C. Levy, Attorney at Law
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8.0 CONSULTANT RECOMMENDATION
Based on the information and environmental analysis contained in the Initial Study and Environmental Checklist, we recommend that the Town of Mammoth Lakes prepare a Mitigated Negative Declaration for the Mammoth Yosemite Airport Regional Air Service. We find that the proposed project could have a significant effect on a number of environmental issues, but that mitigation measures have been specified that would reduce such impacts to a less than significant level. We recommend that the second category be selected for the Town of Mammoth Lakes’ determination; refer to Section 3.3, Lead Agency Determination.
March 14, 2008 ___ Date Eddie Torres, INCE Project Manager Planning/Environmental Services RBF Consulting
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